The information in this preliminary prospectus supplement is not complete and may be changed. This preliminary prospectus supplement and the accompanying prospectus are not an offer to sell these securities and we are not soliciting an offer to buy these securities in any jurisdiction where the offer or sale is not permitted.

We are offering $75,000,000 aggregate principal amount of 8.875% Senior Notes due 2022 (the "Additional Notes").

The Additional Notes will bear interest from March 30, 2019 until maturity at a rate of 8.875% per year. Interest on the Additional Notes will be payable quarterly in arrears on the day of March 30, June 30, September 30 and December 30 of each year, commencing on June 30, 2019. The Additional Notes will be issued in minimum denominations of $1,000 and integral multiples of $1,000 in excess thereof. The Additional Notes will be an additional issuance of, form a single series with and have the same terms as the $250,000,000 8.875% Senior Notes due 2022 we issued on March 22, 2017 (the "Existing Notes" and together with the Additional Notes, the "Notes"). The Additional Notes offered hereby will have the same CUSIP number as the Existing Notes, will trade interchangeably with the Existing Notes and immediately upon settlement, will increase the aggregate principal amount of the Notes outstanding to $325,000,000. The Additional Notes offered hereby and the Existing Notes previously issued by us will constitute a single series under the Indenture for all purposes.

The Notes will be our unsecured unsubordinated obligations. The Notes will rank senior to any of our future subordinated debt and rank equally in right of payment with all of our existing and future unsecured and unsubordinated debt. The Notes will effectively rank junior to our existing and future secured debt to the extent of the value of the assets securing such debt as well as to existing and future debt and other liabilities of our subsidiaries.

We may redeem some or all of the Notes at any time and from time to time at a redemption price of 100% of the principal amount, plus accrued and unpaid interest, if any, to but excluding the redemption date, plus an applicable "make-whole" premium. The Notes may also be redeemed at 100% of their principal amount in whole but not in part upon the occurrence of certain tax events described in this prospectus supplement and the accompanying prospectus.

Investing in the Notes involves a high degree of risk. The Notes have not been rated. Please read the section entitled "Risk Factors" on page S-15 of this prospectus supplement and beginning on page 6 of our Annual Report on Form 20-F filed with the Securities and Exchange Commission on March 5, 2019 before you make an investment in the Notes.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus supplement or the accompanying prospectus are truthful or complete. Any representation to the contrary is a criminal offense.

This document is in two parts. The first part is this prospectus supplement, which describes the specific terms of this offering and certain other matters. The second part, the prospectus, gives more general information about securities we may offer from time to time. Generally, when we refer to the "prospectus", we are referring to both parts of this document combined. You should read both this prospectus supplement and the accompanying prospectus, together with additional information described under the heading "Where You Can Find Additional Information" and "Incorporation by Reference". To the extent the description of our securities in this prospectus supplement differs from the description of our securities in the accompanying prospectus, you should rely on the information in this prospectus supplement.

You should rely only on the information contained or incorporated by reference in this prospectus supplement and the accompanying prospectus. We have not, and the underwriters have not, authorized anyone to provide you with different information. The distribution of this prospectus and sale of these securities in certain jurisdictions may be restricted by law. Persons in possession of this prospectus supplement or the accompanying prospectus are required to inform themselves about and observe any such restrictions. We are not making an offer to sell these securities in any jurisdiction where the offer or sale is not permitted. You should assume that the information appearing in this prospectus supplement is accurate as of the date on the front cover of this prospectus supplement only. Our business, financial condition, results of operations and prospects may have changed since that date.

SUMMARY

This summary highlights information contained elsewhere in this prospectus supplement and the accompanying prospectus and should be read together with the information contained in other parts of this prospectus supplement, the accompanying prospectus and the documents we incorporate by reference, including the risk factors on page S-15 of this prospectus supplement and beginning on page 6 of our Annual Report on Form 20-F filed with the U.S. Securities and Exchange Commission (the "SEC"), on March 5, 2019 ("Annual Report on Form 20-F").

Unless otherwise indicated, reference in this prospectus supplement to:

•: "GasLog", the "Company", the "Group", the "Issuer", "we", "our", "us" or similar terms refers to GasLog Ltd. or any one or more of its subsidiaries (including GasLog Partners LP) or their predecessors, or to such entities collectively, except that when such terms are used in this prospectus supplement in reference to the common shares, the 8.75% Series A Cumulative Redeemable Perpetual Preference Shares (the "Series A Preference Shares") or the Notes, they refer to GasLog Ltd.;
•: "GasLog Partners" or the "Partnership", refers to GasLog Partners LP, a master limited partnership formed by GasLog to acquire, own and operate liquefied natural gas, or "LNG", carriers under multi-year charters, or any one or more of GasLog Partners' subsidiaries;
•: the "general partner" refers to GasLog Partners GP LLC, the general partner of GasLog Partners;
•: "GasLog LNG Services" refers to GasLog LNG Services Ltd., our wholly owned subsidiary;
•: "our vessels" or "our ships" refers to the LNG carriers owned or controlled by the Company and its subsidiaries, including the LNG carriers owned by GasLog Partners; "our wholly owned vessels" or "our wholly owned ships" refers to the LNG carriers owned by the Company and its subsidiaries, excluding any LNG carriers owned by GasLog Partners (in which we hold the controlling general partner interest as well as limited partner interests) and its subsidiaries and Egypt LNG Shipping Ltd. (in which we hold a 25.0% equity interest);
•: "Shell" refers to Royal Dutch Shell plc, or any one or more of its subsidiaries;
•: "BG Group" refers to BG Group plc. BG Group was acquired by Shell on February 15, 2016;
•: "MSL" refers to Methane Services Limited, a subsidiary of Shell;
•: "Samsung" refers to Samsung Heavy Industries Co., Ltd. or any one or more of its subsidiaries;
•: "Total" refers to Total Gas & Power Chartering Limited, a wholly owned subsidiary of Total S.A.;
•: "Centrica" refers to Pioneer Shipping Limited, a wholly owned subsidiary of Centrica plc;
•: "Cheniere" refers to Cheniere Energy, Inc. or any one or more of its subsidiaries;
•: "Trafigura" refers to Trafigura Maritime Logistics PTE Ltd.;
•: "Endesa" refers to Endesa, S.A. or any one or more of its subsidiaries;
•: "JERA" refers to JERA Co., Inc. or any one or more of its subsidiaries;
•: "Egypt LNG" refers to Egypt LNG Shipping Ltd.;
•: "Gastrade" refers to Gastrade S.A.;
•: "the Cool Pool" refers to The Cool Pool Limited;
•: "Ceres Shipping" refers to Ceres Shipping Ltd.;
•: "NYSE" refers to the New York Stock Exchange;

•: "SEC" refers to the U.S. Securities and Exchange Commission;
•: "IFRS" refers to International Financial Reporting Standards;
•: "IASB" refers to International Accounting Standards Board;
•: "dollars" and "$" refers to, and amounts are presented in, U.S. dollars;
•: "LNG" refers to liquefied natural gas;
•: "FSRUs" refers to Floating Storage and Regasification Units;
•: "TFDE" refers to tri-fuel diesel electric engine propulsion;
•: "Steam" refers to steam-powered engine propulsion;
•: "cbm" refers to cubic meters;
•: "X-DF" refers to low pressure, dual-fuel two stroke engine propulsion manufactured by Winterthur Gas & Diesel. Previously referred to as LP-2S;
•: "Dynagas" refers to Dynagas Ltd. and "Golar" refers to Golar LNG Ltd.; and
•: "Mitsui" refers to Mitsui Co., Ltd. and "Lepta Shipping" refers to Lepta Shipping Co., Ltd., a subsidiary of Mitsui.

Our Company

We are an international owner, operator and manager of LNG carriers providing support to international energy companies as part of their LNG logistics chain. Our owned and bareboat fleet as of May 13, 2019 consists of 35 LNG carriers, including 27 ships on the water and eight LNG carriers on order at one of the world's leading LNG shipbuilders, Samsung. This includes 15 LNG carriers in operation that are owned by our NYSE-listed subsidiary GasLog Partners, with which we have entered into certain agreements governing our relationship, including purchase options for certain of our ships. We currently manage and operate 27 LNG carriers including 11 of our wholly owned ships in operation, 14 ships contributed or sold to the Partnership (one is managed by a subsidiary of Shell), one additional LNG carrier in which we have a 25.0% interest and a vessel secured under a long-term bareboat charter from Lepta Shipping, a subsidiary of Mitsui. We are also supervising the construction of our newbuildings. We have secured multi-year contracts for six of our owned ships, 14 of the 15 ships owned by the Partnership, all eight of our newbuildings on order and the one vessel secured under a long-term bareboat charter with Lepta Shipping. As of March 31, 2019 these contracts are expected to provide total contracted revenues of $4.0 billion during their initial terms, which expire between 2019 and 2029.

The LNG carrier in which we have a 25.0% interest is the Methane Nile Eagle, a 2007-built LNG carrier technically managed by us that is currently operating under a 20-year time charter to MSL.

Our current time charters have initial terms of up to ten years and include options that permit the charterers to extend the terms for successive periods under hire rate provisions. We will continue to evaluate the attractiveness of longer and shorter-term chartering opportunities as the commercial characteristics of the LNG carrier industry evolve. Our order book of new LNG carriers has staggered delivery dates, facilitating a smooth integration of the ships into our fleet as well as significant annual growth through 2021. This has the additional advantage of spreading our exposure to the re-employment of these ships over several years upon expiration of their current charters.

Each of our 27 owned and bareboat LNG carriers and eight LNG carriers under construction is designed with a capacity of between approximately 145,000 cbm and 180,000 cbm. We believe this size range maximizes their operational flexibility as these ships are compatible with most existing LNG

terminals around the world. All but one of the LNG carriers in our owned and bareboat fleet are of similar specifications, which allows us to benefit from economies of scale and operating efficiencies in ship construction, crew training, crew rotation and shared spare parts. Upon delivery of the last of our eight contracted newbuildings, our owned fleet will have an average age of 6.9 years, making it one of the youngest in the industry. By comparison, as of December 31, 2018, the average age for the global fleet of LNG carriers, including LNG carriers of all sizes, was 9.9 years.

Our wholly owned subsidiary, GasLog LNG Services, exclusively handles the technical management of our fleet, including plan approval for new ship orders, supervision of ship construction and planning and supervision of dry-dockings, as well as technical operations, crewing, training, maintenance, regulatory and classification compliance and health, safety, security and environmental, or "HSSE", management and reporting. With over 18 years of technical management experience, including 15 years as sole technical manager of BG Group's owned fleet of LNG carriers, we have established a track record for the efficient, safe and reliable operation of LNG carriers which is evidenced by our safety performance and the limited off-hire days of the 27 ships currently operating under our management.

In 2018, GasLog continued the development of an FSRU business, acting on its strategic decision to enter this business segment.

A wholly owned subsidiary of GasLog acquired a 20% shareholding in Gastrade in 2016. Subsequently in 2018, a wholly owned subsidiary of GasLog executed an FSRU Operation and Maintenance Agreement with Gastrade. Gastrade is licensed to develop an independent natural gas system offshore Alexandroupolis in Northern Greece utilizing an FSRU along with other fixed infrastructure. A Front End Engineering and Design study in 2017 by Wood Group and GasLog as subcontractor for the FSRU part of the study confirmed the selected offshore concept.

On May 3, 2018, DEPA, the Greek State Gas Company, and Gastrade signed an agreement regarding the future capacity reservation by DEPA in the Alexandroupolis FSRU. In September, negotiations for the acquisition of 20% of the shares in Gastrade by DEPA was concluded. In December, the Bulgarian parliament approved the acquisition of 20% of the shares in Gastrade by Bulgartransgaz, the Bulgarian State Gas Transport Company. These share acquisitions have not been completed yet.

On December 31, 2018, Gastrade's invitation to express interest in taking long term capacity in the Alexandroupolis FSRU was concluded with responses from 20 companies with an aggregated interest for up to 12.2 billion cubic meters per year of regasification capacity. This is the first phase of a process to secure binding commitment for capacity in the FSRU.

During the first quarter of 2019, there was continued progress on the Alexandroupolis FSRU project workstreams. Preparation for the binding phase of the EU-regulated capacity commitment process (the "Market Test") continued during the period. Expressions of interest ("EOI") for the procurement of the FSRU and the construction of the pipeline and offshore installation have been received and several EOIs have been shortlisted. Tenders for the two separate infrastructure elements of the terminal project are expected to be launched in May. DEPA and Bulgartransgaz are both in the process of formalizing their respective shareholdings in Gastrade. The timing of a Final Investment Decision, which Gastrade had previously guided to mid-2019, is subject to successful conclusions of the workstreams described above, as well as successful completion of financing and state aid discussions and decisions by various regulatory bodies.

GasLog Partners

As of May 13, 2019, the Company holds a 27.6% interest in GasLog Partners and, as a result of its ownership of the general partner and the fact that the general partner elects the majority of the Partnership's directors in accordance with the Partnership's partnership agreement, the Company has

the ability to control the Partnership's affairs and policies. Consequently, GasLog Partners is consolidated in the Company's financial statements.

GasLog Partners hold options to acquire from us 13 additional vessels and will have certain rights to acquire future vessels meeting certain criteria that have charters with a remaining term of at least five years.

Our Fleet

Owned Fleet

The following table presents information about our wholly owned fleet and their associated time charters as of May 13, 2019:

Vessel Name	Year Built	Cargo Capacity (cbm)	Charterer	Propulsion	Charter Expiration⁽¹⁾	Optional Period⁽²⁾

1 Methane Lydon Volney	2006	145,000	Shell	Steam	October 2020	N/A
2 GasLog Savannah	2010	155,000	Spot Market⁽³⁾	TFDE	N/A	N/A
3 GasLog Singapore	2010	155,000	Spot Market⁽³⁾	TFDE	N/A	N/A
4 GasLog Chelsea	2010	153,600	Spot Market⁽³⁾	TFDE	N/A	N/A
5 GasLog Skagen	2013	155,000	Spot Market⁽³⁾	TFDE	N/A	N/A
6 GasLog Saratoga	2014	155,000	Shell	TFDE	September 2019	N/A
7 GasLog Salem	2015	155,000	Spot Market⁽³⁾	TFDE	N/A	N/A
8 GasLog Houston	2018	174,000	Shell	X-DF	May 2028	2031-2034
9 GasLog Hong Kong	2018	174,000	Total	X-DF	December 2025	2028
10 GasLog Genoa	2018	174,000	Shell	X-DF	March 2027	2030-2033
11 GasLog Gladstone	2019	174,000	Shell	X-DF	January 2029	2032-2035

The following table presents information about GasLog Partners' fleet and their associated time charters as of May 13, 2019:

Vessel Name	Year Built		Charterer	Propulsion	Charter Expiration⁽¹⁾	Optional Period⁽²⁾

1 Methane Rita Andrea	2006	145,000	Shell	Steam	April 2020	—
2 Methane Jane Elizabeth	2006	145,000	Shell	Steam	October 2019	—
3 Methane Alison Victoria	2007	145,000	Shell	Steam	December 2019	—
Methane Jane Elizabeth/ Methane Alison Victoria	2006/2007	145,000	Trafigura⁽⁴⁾	Steam	November/ December 2020	2021-2024
4 Methane Shirley Elisabeth	2007	145,000	Shell	Steam	June 2020	—
5 Methane Heather Sally	2007	145,000	Shell	Steam	December 2020	—
6 Methane Becki Anne	2010	170,000	Shell	TFDE	March 2024	2027-2029
7 GasLog Shanghai	2013	155,000	Spot Market⁽³⁾	TFDE	—	—
8 GasLog Santiago	2013	155,000	Trafigura	TFDE	December 2021	2022-2028
9 GasLog Sydney	2013	155,000	Cheniere	TFDE	June 2020	2020-2021
10 GasLog Seattle	2013	155,000	Shell	TFDE	June 2021	—
11 Solaris	2014	155,000	Shell	TFDE	June 2021	—
12 GasLog Greece	2016	174,000	Shell	TFDE	March 2026	2031
13 GasLog Glasgow	2016	174,000	Shell	TFDE	June 2026	2031
14 GasLog Geneva	2016	174,000	Shell	TFDE	September 2023	2028-2031
15 GasLog Gibraltar	2016	174,000	Shell	TFDE	October 2023	2028-2031

Bareboat Vessel

Vessel Name		Year Built			Cargo Capacity (cbm)			Charterer		Propulsion		Charter Expiration⁽¹⁾		Optional Period⁽²⁾

1 Methane Julia Louise⁽⁵⁾			2010			170,000		Shell		TFDE		March 2026		2029-2031

⁽¹⁾: Indicates the expiration of the initial term.
⁽²⁾: The period shown reflects the expiration of the minimum optional period and the maximum optional period. The charterer of the GasLog Santiago may extend the term of this time charter for a period ranging from one to seven years, provided that the charterer provides us with advance notice of declaration. The charterer of the GasLog Sydney may extend the term of this time charter for a period ranging from six to twelve months, provided that the charterer provides us with advance notice of declaration. The charterer of the Methane Becki Anne and the Methane Julia Louise has unilateral options to extend the term of the related time charters for a period of either three or five years at the charterer's election, provided that the charterer provides us with advance notice of declaration of any option in accordance with the terms of the applicable charter. The charterer of the GasLog Greece and the GasLog Glasgow has the right to extend the charters for a period of five years at the charterer's option. The charterer of the GasLog Geneva and the GasLog Gibraltar has the right to extend each charter by two additional periods of five and three years, provided that the charterer provides us with advance notice of declaration. The charterer of the GasLog Houston, the GasLog Genoa and the GasLog Gladstone has the right to extend the charters by two additional periods of three years, provided that the charterer provides us with advance notice of declaration. The charterer of the GasLog Hong Kong has the right to extend the charter for a period of three years, provided that the charterer provides us with advance notice of declaration.
⁽³⁾: Vessels currently operating in the spot market under the Cool Pool.
⁽⁴⁾: On March 22, 2018, a new charter party agreement was signed with Trafigura for either the Methane Jane Elizabeth or the Methane Alison Victoria (as nominated by the Partnership) commencing in either November or December 2019, at the Partnership's option, until November or December 2020, with the charterer having the option to extend the charter from one to four years.
⁽⁵⁾: On February 24, 2016, GasLog's subsidiary, GAS-twenty six Ltd., completed the sale and leaseback of the Methane Julia Louise with Lepta Shipping. Lepta Shipping has the right to on-sell and lease back the vessel. The vessel was sold to Lepta Shipping for a total consideration approximately equivalent to its book value. GasLog has leased back the vessel under a bareboat charter from Lepta Shipping for a period of up to 20 years. GasLog has the option to re-purchase the vessel on pre-agreed terms no earlier than the end of year ten and no later than the end of year 17 of the bareboat charter. The vessel remains on its eleven-year charter with MSL.

Newbuilds

Vessel Name	Date of Delivery⁽¹⁾		Charterer	Propulsion	Charter Expiration⁽²⁾	Optional Period⁽³⁾

1 GasLog Warsaw	Q3 2019	180,000	Endesa⁽⁴⁾	X-DF	2029	2035-2041
2 Hull No. 2213	Q2 2020	180,000	Centrica	X-DF	2027	2029-2033
3 Hull No. 2274	Q2 2020	180,000	JERA	X-DF	2032	2035-2038
4 Hull No. 2262	Q3 2020	180,000	Centrica	X-DF	2027	2029-2033
5 Hull No. 2300	Q4 2020	174,000	Cheniere	X-DF	2027	2030-2034
6 Hull No. 2301	Q4 2020	174,000	Cheniere	X-DF	2027	2030-2034
7 Hull No. 2311	Q2 2021	180,000	Cheniere	X-DF	2028	2031-2035
8 Hull No. 2312	Q3 2021	180,000	Cheniere	X-DF	2028	2031-2035

⁽¹⁾: Expected delivery quarters are presented.
⁽²⁾: Indicates the expiration of the initial term.
⁽³⁾: The charterer of the GasLog Warsaw has the right to extend the charter by two consecutive periods of six years at the charterer's option. The charterer of Hull No. 2213 and Hull No. 2262 has the right to extend the charters by three consecutive periods of two years each at the charterer's option. The charterer of Hull No. 2274 has the right to extend the charter by two consecutive periods of three years at the charterer's option. The charterer of Hull Nos. 2300, 2301, 2311 and 2312 has the right to extend the charters by three consecutive periods of three years, two years and two years, respectively, each at the charterer's option.
⁽⁴⁾: The vessel is chartered to a wholly owned subsidiary of Endesa. The charter will commence in May 2021.

The key characteristics of our owned fleet include the following:

•: each ship is sized at between approximately 145,000 cbm and 180,000 cbm capacity, which places our ships in the medium- to large-size class of LNG carriers; we believe this size range maximizes their efficiency and operational flexibility, as these ships are compatible with most existing LNG terminals around the world;
•: each ship is double-hulled, which is standard in the LNG industry;
•: each ship has a membrane containment system incorporating current industry construction standards, including guidelines and recommendations from Gaztransport and Technigaz (the designer of the membrane system) as well as updated standards from our classification society;
•: each of our ships is equipped with a modern steam turbine or has TFDE or X-DF engine propulsion technology;
•: Bermuda is the flag state of each delivered ship;
•: each of our delivered ships has received, and each of our newbuildings is expected to receive, an ENVIRO+ notation from our classification society, which denotes compliance with its published guidelines concerning the most stringent criteria for environmental protection related to design characteristics, management and support systems, sea discharges and air emissions; and
•: upon delivery of the last of our eight contracted newbuildings in 2021, our owned fleet will have an average age of 6.9 years, making it one of the youngest in the industry, compared to a current average age of 9.9 years for the global LNG carrier fleet including LNG carriers of all sizes as of December 31, 2018.

In addition to our owned fleet, we have a 25% ownership interest in Egypt LNG, an entity whose principal asset is the Methane Nile Eagle. The Methane Nile Eagle is a 145,000 cbm LNG carrier that was built in 2007. It is currently chartered to MSL under a 20-year time charter, which is subject to extension for up to 10 years at the charterer's option.

We continually evaluate short and long-term charter opportunities for our vessels. Our discussions with potential charterers are at various stages of advancement; however, as of the date of this prospectus supplement, we cannot provide assurance that we will conclude any particular charter or, if concluded, the charter rate that will apply.

Managed Fleet

Through GasLog LNG Services, we provide technical ship management services for one LNG carrier owned by a third party in addition to management of the 26 LNG carriers currently operating in our owned and bareboat fleet (the Solaris is managed by a subsidiary of Shell). We supervised the construction of each LNG carrier in our managed fleet, and each ship has operated under our technical management since its delivery from the shipyard with the exception of the Solaris.

The following table provides information about our managed, third party owned ship (not including the bareboat vessel):

Vessel Name		Year Built			Cargo Capacity (cbm)			Propulsion		GasLog Ownership			Ship Owner

Methane Nile Eagle⁽¹⁾			2007			145,000		Steam			25.0	%	Egypt LNG⁽¹⁾

⁽¹⁾: The Methane Nile Eagle is owned by Egypt LNG, in which we indirectly hold a 25.0% equity interest. Shell Integrated Gas Thailand PTE. Ltd., a subsidiary of Shell, and Eagle Gas Shipping Co. E.S.A., an entity affiliated with the government of Egypt, have 25.0% and 50.0% equity interests, respectively, in Egypt LNG.

Our Relationship to Our Controlling Shareholders

Our chairman, Peter G. Livanos, is our largest shareholder through his ownership of Ceres Shipping, which has a majority ownership interest in Blenheim Holdings Ltd., or "Blenheim Holdings". The shipping activities of the Livanos family commenced more than 100 years ago, and Ceres Shipping also has interests in tankers, dry bulk carriers and containerships. Ceres Shipping's LNG shipping activities commenced in 2001, and its operations in the LNG shipping sector are conducted exclusively through GasLog. Entities controlled by members of the Livanos family, including our chairman, are deemed to beneficially own approximately 40.27% of our issued and outstanding common shares. As a result of his ownership of our common shares, Mr. Livanos can effectively control the outcome of most matters on which GasLog's shareholders are entitled to vote.

Anthony Papadimitriou, a member of our Board, was originally designated by the Onassis Foundation to serve as one of our directors. The Onassis Foundation beneficially owns 8.80% of our issued and outstanding common shares.

Corporate Information

We maintain our principal executive offices at Gildo Pastor Center, 7 Rue du Gabian, MC 98000, Monaco. Our telephone number at that address is +377 97 97 51 15. We are registered with the Registrar of Companies in Bermuda under registration number 33928. We maintain a registered office in Bermuda at Clarendon House, 2 Church Street, Hamilton, HM 11, Bermuda.

The Offering


Issuer		GasLog Ltd.
Securities Offered		$75.0 million aggregate principal amount of our 8.875% Senior Notes due 2022 issued in minimum denominations of $1,000 and integral multiples of $1,000 in excess thereof. For a detailed description of the Notes, see "Description of Notes".
		The Additional Notes offered hereby will have the same CUSIP number as the Existing Notes, will trade interchangeably with the Existing Notes and immediately upon settlement, will increase the aggregate principal amount of the Notes outstanding to $325,000,000.
Maturity Dates		The Notes will mature on March 22, 2022.
Interest Payment Dates		March 30, June 30, September 30 and December 30 of each year, commencing on June 30, 2019.
Interest Rate		The Additional Notes will bear interest from March 30, 2019 until maturity at a rate of 8.875% per year, payable quarterly in arrears.
Ranking		The Notes will be unsecured unsubordinated obligations of GasLog. The Notes will rank senior to any of our future subordinated debt and rank equally in right of payment with all of our existing and future unsecured and unsubordinated debt. The Notes will effectively rank junior to our existing and future secured debt to the extent of the value of the assets securing such debt as well as to existing and future debt and other liabilities of our subsidiaries. As of March 31, 2019, after giving effect to the issuance of the Additional Notes and the use of proceeds thereof as described under "Use of Proceeds", we would have had total consolidated debt of approximately $ billion. Of such amount, approximately $2.6 billion would have been secured bank debt and $0.2 billion would have been finance lease liabilities, all of which is debt of our subsidiaries.
No Security or Guarantees		None of our obligations under the Notes will be secured by collateral or guaranteed by any of our subsidiaries, affiliates or any other persons.
Change of Control		Upon the occurrence of certain change of control events (as defined in the indenture governing the Notes), you will have the right, as a holder of the Notes, to require us to repurchase some or all of your Notes at 101% of the principal amount, plus accrued and unpaid interest to, but excluding, the repurchase date. For additional information, please read "Description of Notes—Change of Control Permits Holders to Require the Issuer to Purchase Notes".


Optional Redemption		We may redeem some or all of the Notes at any time and from time to time at a redemption price of 100% of their principal amount, plus accrued and unpaid interest, if any, to but excluding the redemption date, plus an applicable "make-whole" premium. For additional information, please read "Description of Notes—Optional Redemption".
Covenants		The indenture governing the Notes contains certain restrictive covenants, including covenants that require us to maintain a certain amount of asset coverage and provide certain reports. For additional information, please read "Description of Notes".
"Reopening" of Notes		For U.S. federal income tax purposes, we intend to treat the issuance of the Additional Notes as a "qualified reopening" of our Existing Notes, which were issued originally on March 22, 2017. We may "reopen" the Notes at any time without the consent of the holders of the Notes and issue additional notes with the same terms as the Notes (except the issue price, issue date and initial interest payment date), which will thereafter constitute a single fungible series with the Notes.
Use of Proceeds		We intend to use the net proceeds of the sale of the Additional Notes, which, after deducting underwriting discounts and the estimated expenses payable by us, are expected to total approximately $ , to partially fund the company's committed growth capital program and for general corporate purposes, including working capital.
Ratings		The Notes will not be rated by any Nationally Recognized Statistical Rating Organization.
Listing		The Notes will not be listed on any securities exchange.
Form		The Notes will be represented by one or more permanent global notes, which will be deposited with the trustee as custodian for The Depository Trust Company, or DTC, and registered in the name of Cede & Co., as a nominee designated by DTC. Holders of Notes may hold interests in a global Note only in the manner described in this prospectus. Any such interest may not be exchanged for certificated securities except in limited circumstances described in this prospectus supplement. For additional information, please read "Description of Notes—Book-Entry System; Delivery and Form" in this prospectus supplement.


Additional Amounts; Tax Redemption		Any payments made by us with respect to the Notes will be made without withholding or deduction for or on account of taxes unless required by law. If we are required by law to withhold or deduct amounts for or on account of tax imposed by a relevant taxing authority with respect to a payment to the holders of Notes, we will, subject to certain exceptions, pay the additional amounts necessary so that the net amount received by the holders of the Notes after the withholding or deduction is not less than the amount that they would have received in the absence of the withholding or deduction. Please read "Description of Notes—Additional Amounts".
		In the event of certain developments affecting taxation, we may redeem the Notes in whole, but not in part, at any time, at a redemption price of 100% of the principal amount, plus accrued and unpaid interest, if any, to the date of redemption. Please read "Description of Notes—Optional Redemption for Changes in Withholding Taxes".
Settlement		Delivery of the Notes offered hereby will be made against payment therefor on or about , 2019.
Risk Factors		An investment in the Notes involves risks. You should consider carefully the factors set forth in the section of this prospectus supplement entitled "Risk Factors" beginning on page S-15 of this prospectus supplement to determine whether an investment in the Notes is appropriate for you.

Summary Consolidated Financial and Other Data

The following table presents, in each case for the periods and as of the dates indicated, summary consolidated financial and operating data. The summary consolidated financial data of GasLog as of December 31, 2017 and 2018, and for each of the years in the three year period ended December 31, 2018, is derived from our audited consolidated financial statements and notes thereto included in "Item 18. Financial Statements" of our Annual Report on Form 20-F for the year ended December 31, 2018, which is incorporated by reference. The summary consolidated financial data as of December 31, 2014, 2015 and 2016, and for the years ended December 31, 2014 and 2015, is derived from our audited consolidated financial statements, which are not included in our Annual Report on Form 20-F. The summary historical financial data of GasLog as of March 31, 2019 and for the three-month periods ended March 31, 2018 and 2019 has been derived from the unaudited interim condensed consolidated financial statements of GasLog included in Exhibit 99.2 of our Report on Form 6-K furnished to the SEC on May 3, 2019, which is incorporated by reference. Our consolidated financial statements are prepared and presented in accordance with IFRS, as issued by the IASB.

This information should be read together with, and is qualified in its entirety by, our consolidated financial statements and the notes thereto included in "Item 18. Financial Statements" of our Annual Report on Form 20-F for the year ended December 31, 2018, and incorporated by reference and the unaudited interim condensed consolidated financial statements of GasLog included in Exhibit 99.2 of our Report on Form 6-K furnished to the SEC on May 3, 2019 and incorporated by reference. You

should also read "Item 5. Operating and Financial Review and Prospects" of our Annual Report on Form 20-F for the year ended December 31, 2018, which is incorporated by reference.

	Year Ended December 31,															Three Months Ended March 31,

	2014			2015			2016			2017			2018			2018			2019
	(in thousands of U.S. dollars, except share and per share data)
CONSOLIDATED STATEMENT OF PROFIT OR LOSS
Revenues	$	328,679		$	415,078		$	466,059		$	525,229		$	618,344		$	138,478		$	166,547
Net pool allocation		—			—			(4,674	)		7,254			17,818			8,653			(6,738	)
Voyage expenses and commissions		(7,738	)		(14,290	)		(10,510	)		(15,404	)		(20,374	)		(5,281	)		(6,917	)
Vessel operating and supervision costs		(70,732	)		(98,552	)		(112,632	)		(122,486	)		(128,084	)		(34,313	)		(32,970	)
Depreciation		(70,695	)		(106,641	)		(122,957	)		(137,187	)		(153,193	)		(35,529	)		(39,599	)
General and administrative expenses		(34,154	)		(41,282	)		(38,642	)		(39,850	)		(41,993	)		(12,013	)		(10,377	)

Profit from operations		145,360			154,313			176,644			217,556			292,518			59,995			69,946

Financial costs		(71,579	)		(91,956	)		(137,316	)		(139,181	)		(166,627	)		(36,597	)		(45,507	)
Financial income		274			427			720			2,650			4,784			1,016			1,459
(Loss)/gain on derivatives		(24,787	)		(10,332	)		(13,419	)		2,025			(6,077	)		17,771			(20,244	)
Share of profit of associates		1,497			1,216			1,422			1,159			1,800			356			245

Total other expenses, net		(94,595	)		(100,645	)		(148,593	)		(133,347	)		(166,120	)		(17,454	)		(64,047	)

Profit for the year	$	50,765		$	53,668		$	28,051		$	84,209		$	126,398		$	42,541		$	5,899



Profit/(loss) attributable to owners of the Group	$	42,161		$	10,829		$	(21,486	)	$	15,506		$	47,683		$	19,304		$	(10,947	)
Profit attributable to non-controlling interests	$	8,604		$	42,839		$	49,537		$	68,703		$	78,715		$	23,237		$	16,846
Earnings/(loss) per share, basic	$	0.54		$	0.04		$	(0.39	)	$	0.07		$	0.47		$	0.21		$	(0.17	)
Earnings/(loss) per share, diluted	$	0.54		$	0.04		$	(0.39	)	$	0.07		$	0.46		$	0.21		$	(0.17	)
Weighted average number of shares, basic		78,633,820			80,496,314			80,534,702			80,622,788			80,792,837			80,715,130			80,825,637
Weighted average number of shares, diluted		78,800,192			80,610,420			80,534,702			81,266,130			81,637,022			81,497,291			80,825,637
Dividends declared per common share	$	0.50		$	0.56		$	0.56		$	0.56		$	0.59		$	0.14		$	0.15
Dividends declared per preference share	$	—		$	1.60		$	2.19		$	2.19		$	2.19		$	0.55		$	0.55
Special dividends declared per common share	$	—		$	—		$	—		$	—		$	0.40		$	—		$	—

	As of December 31,										As of March 31,

	2014		2015		2016		2017		2018		2019
	(in thousands of U.S. dollars)
CONSOLIDATED STATEMENT OF FINANCIAL POSITION DATA
Cash and cash equivalents	$	211,974	$	302,988	$	227,024	$	384,092	$	342,594	$	230,750
Short-term investments		28,103		6,000		18,000		—		25,000		10,000
Restricted cash		22,826		62,718		42		—		—		—
Investment in associates⁽¹⁾		6,603		6,274		6,265		20,800		20,713		20,958
Tangible fixed assets⁽²⁾		2,809,517		3,400,270		3,889,047		3,772,566		4,323,582		4,500,415
Vessels under construction		142,776		178,405		96,356		166,655		159,275		155,841
Right-of-use assets		—		—		222,004		214,329		206,753		212,918
Total assets		3,269,971		4,039,621		4,515,164		4,634,891		5,174,807		5,194,470
Borrowings, current portion		116,431		636,987		147,448		179,367		520,550		172,686
Borrowings, non-current portion		1,778,845		1,737,500		2,504,578		2,368,189		2,307,909		2,748,035
Lease liability, current portion		—		—		5,946		6,302		6,675		8,959
Lease liability, non-current portion		—		—		214,455		207,126		199,424		203,100
Share capital		810		810		810		810		810		810
Preference Shares		—		46		46		46		46		46
Equity attributable to owners of the Group		929,391		1,001,674		945,643		918,029		879,742		850,540
Non-controlling interests		323,646		506,246		564,039		845,105		1,103,380		1,093,729
Total equity		1,253,037		1,507,920		1,509,682		1,763,134		1,983,122		1,944,269

	Year Ended December 31,															Three Months Ended March 31,

	2014			2015			2016			2017			2018			2018			2019
	(in thousands of U.S. dollars)
CONSOLIDATED CASH FLOW DATA
Net cash provided by operating activities	$	148,288		$	161,579		$	256,532		$	223,630		$	283,710		$	43,278		$	42,714
Net cash used in investing activities		(1,386,656	)		(704,052	)		(771,242	)		(74,599	)		(692,999	)		(560,937	)		(198,019	)
Net cash provided by financing activities		1,346,762			634,317			439,766			7,265			368,120			482,255			43,592

	Year Ended December 31,										Three Months Ended March 31,

	2014		2015		2016		2017		2018		2018		2019
FLEET DATA⁽³⁾
Number of managed ships at end of period		21		22		25		23		26		26		27
Average number of managed ships during period		20.0		21.7		23.6		23.4		25.5		24.1		26.2
Number of owned ships at end of period		16		19		22		22		25		25		26
Average number of owned ships during period		12.4		18.2		19.8		22		24.5		23.0		25.2
Average age of owned ships (years)		4.4		5.2		5.1		6.1		6.4		5.6		6.3
Total calendar days for owned and bareboat fleet		4,520		6,638		7,568		8,395		9,318		2,168		2,356
Total operating days for owned and bareboat fleet⁽⁴⁾		4,392		6,097		7,439		8,317		9,030		2,162		2,350

	Year Ended December 31,										Three Months Ended March 31,

	2014		2015		2016		2017		2018		2018		2019
	(in thousands of U.S. dollars)
OTHER FINANCIAL DATA
EBITDA⁽⁵⁾	$	217,552	$	262,170	$	301,023	$	355,902	$	447,511	$	95,880	$	109,790
Adjusted EBITDA⁽⁵⁾		217,172		262,969		302,386		356,048		447,747		95,526		109,940
Capital expenditures:
Payments for fixed assets		1,364,283		728,446		761,513		82,352		673,823		547,021		220,549
Common share dividend declared		39,840		45,078		45,101		45,144		80,011		11,300		12,129
Preference share dividend declared		—		7,379		10,063		10,064		10,063		2,516		2,516

⁽¹⁾: Consists of our 25.0% ownership interest in Egypt LNG, our 50.0% ownership interest in the Cool Pool and our investment in Gastrade. On October 1, 2015, GasLog, Dynagas and Golar signed an LNG carrier pooling agreement to establish the Cool Pool to market their vessels which are currently operating in the LNG shipping spot market. The Cool Pool allows the participating owners to optimize the operation of the pool vessels through improved scheduling ability, cost efficiencies and common marketing. The objective of the Cool Pool is to serve the transportation requirements of a rapidly growing LNG shipping market by providing customers with reliable, yet flexible, and innovative solutions to meet their increasingly complex shipping requirements. The Cool Pool was incorporated in September 2015. In June and July 2018, Dynagas removed its three vessels from the Cool Pool and renounced its 33% ownership in the Cool Pool. Gastrade is a private limited company licensed to develop an independent natural gas system offshore Alexandroupolis in Northern Greece utilizing an FSRU along with other fixed infrastructure.
⁽²⁾: Includes delivered ships (including dry-docking component of vessel cost) as well as office property and other tangible assets, less accumulated depreciation.
⁽³⁾: Presentation of fleet data does not include newbuildings on order during the relevant periods. The data presented regarding our owned fleet includes only our owned ships delivered prior to March 31, 2019 including the ships owned by GasLog Partners. The data presented regarding our managed fleet includes our wholly owned vessels as well as ships owned by GasLog Partners, Egypt LNG and Lepta Shipping that are or were operating under our management.
⁽⁴⁾: The operating days for our owned and bareboat fleet are the total number of days in a given period that the vessels (including the Methane Julia Louise, our vessel on a bareboat charter) were in our possession less the total number of days off-hire not recoverable from the insurers. In 2018, operating days include 2,046 days for our vessels operating in the Cool Pool. We define days off-hire as days lost to, among other things, operational deficiencies, dry-docking for repairs, maintenance or inspection, equipment breakdowns, special surveys and vessel upgrades, delays due to accidents, crew strikes, certain vessel detentions or similar problems, our failure to maintain the vessel in compliance with its specifications and contractual standards or to provide the required crew, or periods of commercial waiting time during which we do not earn charter hire.

⁽⁵⁾

Non-GAAP Financial Measures:

EBITDA is defined as earnings before depreciation, amortization, financial income and costs, gain/loss on derivatives and taxes. Adjusted EBITDA is defined as EBITDA before foreign exchange gains/losses. EBITDA and Adjusted EBITDA are non-GAAP financial measures that are used as supplemental financial measures by management and external users of financial statements, such as investors, to assess our financial and operating performance. We believe that these non-GAAP financial measures assist our management and investors by increasing the comparability of our performance from period to period. We believe that including EBITDA and Adjusted EBITDA assists our management and investors in (i) understanding and analyzing the results of our operating and business performance, (ii) selecting between investing in us and other investment alternatives and (iii) monitoring our ongoing financial and operational strength in assessing whether to continue to hold our common shares. This is achieved by excluding the potentially disparate effects between periods of financial costs, gain/loss on derivatives, taxes, depreciation and amortization, and, in the case of Adjusted EBITDA, foreign exchange gains/losses, which items are affected by various and possibly changing financing methods, capital structure and historical cost basis and which items may significantly affect results of operations between periods.

EBITDA and Adjusted EBITDA have limitations as analytical tools and should not be considered as alternatives to, or as substitutes for, or superior to, profit, profit from operations or any other measure of financial performance presented in accordance with IFRS. Some of these limitations include the fact that they do not reflect (i) our cash expenditures or future requirements for capital expenditures or contractual commitments, (ii) changes in, or cash requirements for, our working capital needs and (iii) the cash requirements necessary to service interest or principal payments, on our debt. Although depreciation and amortization are non-cash charges, the assets being depreciated and amortized will have to be replaced in the future, and EBITDA and Adjusted EBITDA do not reflect any cash requirements for such replacements. EBITDA and Adjusted EBITDA are not adjusted for all non-cash income or expense items that are reflected in our statements of cash flows and other companies in our industry may calculate these measures differently than we do, limiting their usefulness as a comparative measure.

In evaluating Adjusted EBITDA, you should be aware that in the future we may incur expenses that are the same as or similar to some of the adjustments in this presentation. Our presentation of Adjusted EBITDA should not be construed as an inference that our future results will be unaffected by the excluded items. Therefore, the non-GAAP financial measures as presented below may not be comparable to similarly titled measures of other companies in the shipping or other industries.

Reconciliation of EBITDA and Adjusted EBITDA to Profit:

	Year Ended December 31,															Three Months Ended March 31,

	2014			2015			2016			2017			2018			2018			2019
	(in thousands of U.S. dollars)
Profit for the period	$	50,765		$	53,668		$	28,051		$	84,209		$	126,398		$	42,541		$	5,899
Depreciation		70,695			106,641			122,957			137,187			153,193			35,529			39,599
Financial costs		71,579			91,956			137,316			139,181			166,627			36,597			45,507
Financial income		(274	)		(427	)		(720	)		(2,650	)		(4,784	)		(1,016	)		(1,459	)
Loss/(gain) on derivatives		24,787			10,332			13,419			(2,025	)		6,077			(17,771	)		20,244

EBITDA		217,552			262,170			301,023			355,902			447,511			95,880			109,790
Foreign exchange (gains)/losses, net		(380	)		799			1,363			146			236			(354	)		150

Adjusted EBITDA	$	217,172		$	262,969		$	302,386		$	356,048		$	447,747		$	95,526		$	109,940

Any investment in the Notes involves a high degree of risk. You should carefully consider the important factors set forth under the heading "Risk Factors" starting on page 6 of our Annual Report on Form 20-F for the year ended December 31, 2018, which was filed with the SEC on March 5, 2019 and incorporated herein by reference, before investing in the Notes. For further details, see the sections entitled "Where You Can Find Additional Information" and "Incorporation by Reference".

Any of the risk factors referred to above could significantly and negatively affect our business, results of operations or financial condition. The risks referred to above are not the only ones that may exist. Additional risks not currently known by us or that we deem immaterial may also impair our business operations. You may lose all or a part of your investment. In addition, potential investors should consider the following risks and uncertainties with respect to your investment in the Notes.

The Notes are unsubordinated unsecured general obligations of ours and are not, either directly or indirectly, an obligation of any third party. The Notes will rank equally with all of our other unsecured and unsubordinated debt obligations. Any payment to be made on the Notes, including the return of the principal amount at maturity or any redemption date, as applicable, depends on our ability to satisfy our obligations as they come due. As a result, our actual and perceived creditworthiness may affect the market value of the Notes and, in the event we were to default on our obligations, you may not receive the amounts owed to you under the terms of the Notes.

The amount of our debt could limit our liquidity and flexibility in obtaining additional financing and in pursuing other business opportunities.

As of March 31, 2019, we had total outstanding consolidated debt of $3.1 billion, including $0.2 billion of finance lease liabilities. We also have undrawn available capacity under the Legacy Facility Refinancing (as defined below in "Description of Other Indebtedness") and the 2019 GasLog Partners Facility (as defined below in "Description of Other Indebtedness"). We are obligated to make substantial capital expenditures to fund our commitments for the eight newbuildings we have on order, and any additional ships we may acquire or build in the future. As of March 31, 2019, the total remaining balance of the contract prices for the eight vessels was $1,343.6 million, which we intend to fund with available cash, cash from operations and new debt facilities. We expect that a large portion of our cash flow from operations will also be used to repay the principal and interest on our debt, a substantial portion of which matures prior to the Notes. In addition, we may enter into other new debt arrangements or issue additional debt securities in the future. So long as our total indebtedness does not exceed 75% of our total capitalization, the indenture under which the Notes will be issued will permit us to incur additional indebtedness, subject to certain limitations in our other debt agreements, as described in more detail under "Description of Other Indebtedness".

Our current indebtedness and future indebtedness that we may incur could affect our future operations, as a large portion of our cash flow from operations will be dedicated to the payment of interest and principal on such debt and will not be available for other purposes. Covenants contained in our debt agreements may affect our flexibility in planning for, and reacting to, changes in our business or economic conditions, limit our ability to dispose of assets or place restrictions on the use of proceeds from such dispositions, withstand current or future economic or industry downturns and compete with others in our industry for strategic opportunities, and limit our ability to obtain additional financing for working capital, capital expenditures, acquisitions, general corporate and other purposes and our ability to pay dividends to our shareholders and principal and interest on the Notes to noteholders.

Our ability to service our debt will depend upon, among other things, our future financial and operating performance, which will be affected by prevailing economic conditions and financial, business, regulatory and other factors, some of which are beyond our control. If our operating results are not sufficient to service our current or future indebtedness, we will be forced to take actions such as reducing or eliminating distributions to our shareholders, reducing or delaying our business activities, acquisitions, investments or capital expenditures, selling assets, restructuring or refinancing our debt, or seeking additional equity capital or bankruptcy protection. We may not be able to effect any of these remedies on satisfactory terms, or at all.

Our subsidiaries conduct substantially all of our operations and own all of our operating assets, and your right to receive payments on the Notes is structurally subordinated to the rights of the lenders of our subsidiaries, including GasLog Partners.

We are a holding company. Our subsidiaries conduct substantially all of our operations and own our operating assets, including our ships. As a result, our ability to make required payments on the Notes depends entirely on the operations of our subsidiaries and our subsidiaries' ability to distribute funds to us. To the extent our subsidiaries are unable to distribute, or are restricted from distributing, funds to us, we may be unable to fulfill our obligations under the Notes. Our subsidiaries are separate and distinct legal entities and have no obligation, contingent or otherwise, to pay amounts due on the Notes or to make funds available for that purpose. The Notes will not be guaranteed by any of our subsidiaries or any other person.

The rights of holders of the Notes will be structurally subordinated to the rights of our subsidiaries' lenders. A default by a subsidiary under its debt obligations would result in a block on distributions from the affected subsidiary to us. The Notes will be effectively junior to all existing and future liabilities of our subsidiaries. In the event of a bankruptcy, liquidation or reorganization of any of our subsidiaries, creditors of our subsidiaries will generally be entitled to payment of their claims from the assets of those subsidiaries before any assets are made available for distribution to us. As of March 31, 2019, our subsidiaries had $2.6 billion of outstanding bank debt (all of which was secured) and $0.2 billion of finance lease liabilities. In addition, the indenture under which the Notes will be issued will permit our subsidiaries to incur additional debt, subject to the limitations set forth therein. Please read "Description of Notes—Certain covenants—Limitations on Total Indebtedness".

We may be unable to comply with covenants in our existing or future financing arrangements that impose operating and financial restrictions on us.

Our credit facilities impose, and any future credit facility we enter into will impose, operating and financial restrictions on us and our subsidiaries. These restrictions in our credit facilities generally limit our shipowning subsidiaries' ability to, among other things:

Therefore, we may need to seek permission from our lenders in order to engage in some actions. Our lenders' interests may be different from ours and we may not be able to obtain our lenders' permission when needed. This may limit our ability to pay interest on the Notes, finance our future operations or capital requirements, make acquisitions or pursue business opportunities.

Our credit facilities also impose specific financial covenants that apply to us and our subsidiaries on a consolidated basis or to GasLog Partners and its subsidiaries on a consolidated basis, as the case may be. Further, GasLog has NOK denominated bonds which also impose specified financial covenants that apply to us and our subsidiaries on a consolidated basis.

Our ability to comply with covenants and restrictions contained in our financing arrangements may be affected by events beyond our control, including prevailing economic, financial and industry conditions. A failure to comply with covenants and restrictions, which include an earnings-based financial covenant, or to meet our payment and other obligations could lead to defaults under our debt obligations which could cause our payment obligations to be accelerated. We may not have, or be able to obtain, sufficient funds to make these accelerated payments. Because obligations under our financing arrangements are secured by our ships and are guaranteed by our ship-owning subsidiaries, if we are unable to repay debt under our financing arrangements, the lenders could seek to foreclose on those assets, which would materially and adversely impact our business, financial condition, results of operations and cash flows. In addition, a default under one of our debt obligations could result in the cross-acceleration of our other indebtedness.

Please see "Description of Other Indebtedness" for more information on our existing financing arrangements.

The Notes will be unsecured obligations and will be effectively subordinated to our secured debt.

The Notes are unsecured and therefore will be effectively subordinated to any existing or future secured debt to the extent of the value of the assets securing the debt. In the event of a bankruptcy or similar proceeding involving us, the assets that serve as collateral will be available to satisfy the obligations under any secured debt before any payments are made on the Notes. As of March 31, 2019, we had total outstanding secured bank debt of $2.6 billion and finance lease liabilities of approximately $0.2 billion. We will continue to have the ability to incur additional secured debt, subject to limitations in our financing arrangements and the indenture relating to the Notes. Please read "Description of Other Indebtedness".

We may not have the ability to raise the funds necessary to purchase the Notes as required upon a change of control, and our existing and future debt may contain limitations on our ability to purchase the Notes.

Following a change of control as described under "Description of Notes—Change of Control Permits Holders to Require Issuer to Purchase Notes", holders of Notes will have the right to require us to purchase their Notes for cash at 101% of their principal amount plus accrued and unpaid interest. A change of control may also constitute an event of default or prepayment under, and result in the acceleration of the maturity of, our then existing indebtedness. We cannot assure you that we will have sufficient financial resources, or will be able to arrange financing, to pay the change of control purchase price in cash with respect to any Notes surrendered by holders for purchase upon a change of control. In addition, restrictions in our then existing credit facilities or other indebtedness, if any, may not allow us to purchase the Notes upon a change of control. Our failure to purchase the Notes upon a change of control when required would result in an event of default with respect to the Notes which could, in turn, constitute a default under the terms of our other indebtedness, if any. If the repayment of the

related indebtedness were to be accelerated after any applicable notice or grace periods, we may not have sufficient funds to repay the indebtedness and purchase the Notes.

Some significant restructuring transactions may not constitute a change of control, in which case we would not be obligated to offer to purchase the Notes.

Upon the occurrence of a change of control, you have the right to require us to purchase your Notes. However, the change of control provisions will not afford protection to holders of Notes in the event of certain transactions that could adversely affect the Notes. For example, transactions such as leveraged recapitalizations, refinancings or certain restructurings would not constitute a change of control requiring us to repurchase the Notes. In the event of any such transaction, holders of the Notes would not have the right to require us to purchase their Notes, even though each of these transactions could increase the amount of our indebtedness, or otherwise adversely affect our capital structure or any credit ratings, thereby adversely affecting holders of the Notes.

We do not intend to list the Notes on any securities exchange. The lack of an active trading market could adversely affect your ability to sell the Notes and the price at which you may be able to sell the Notes. The liquidity of the trading market and future trading prices of the Notes will depend on many factors, including, among other things, prevailing interest rates, our operating results, financial performance and prospects, the market for similar securities and the overall securities market, and may be adversely affected by unfavorable changes in these factors. It is possible that the market for the Notes will be subject to disruptions that may have a negative effect on the holders of the Notes, regardless of our operating results, financial performance or prospects.

The Notes have not been rated, and ratings of any of our other securities may affect the trading price of the Notes.

We have not sought to obtain a rating for the Notes, and the Notes may never be rated. It is possible, however, that one or more credit rating agencies might independently determine to assign a rating to the Notes or that we may elect to obtain a rating of the Notes in the future. In addition, we may elect to issue other securities for which we may seek to obtain a rating. If any ratings are assigned to the Notes in the future or if we issue other securities with a rating, such ratings, if they are lower than market expectations or are subsequently lowered or withdrawn, or if ratings for such other securities would imply a lower relative value for the Notes, could adversely affect the market for, or the market value of, the Notes. Ratings only reflect the views of the issuing rating agency or agencies and such ratings could at any time be revised downward or withdrawn entirely at the discretion of the issuing rating agency. A rating is not a recommendation to purchase, sell or hold any particular security, including the Notes. Ratings do not reflect market prices or suitability of a security for a particular investor and any future rating of the Notes may not reflect all risks related to us and our business, or the structure or market value of the Notes.

In addition to the following risk factors, you should read "Material Tax Considerations" for a more complete discussion of the material Bermuda and U.S. Federal income tax considerations relating to us and the Notes.

We may have to pay tax on U.S.-source income, which would reduce our earnings.

Under the United States Internal Revenue Code of 1986, as amended (the "Code"), the U.S. source gross transportation income of a ship-owning or chartering corporation, such as ourselves, is

subject to a 4% U.S. Federal income tax without allowance for deduction, unless that corporation qualifies for exemption from tax under a tax treaty or Section 883 of the Code and the Treasury Regulations promulgated thereunder. U.S. source gross transportation income consists of 50% of the gross shipping income that is attributable to transportation that begins or ends, but that does not both begin and end, in the United States.

GasLog Ltd. has qualified for the statutory tax exemption for the year of 2018 and intends to continue to qualify for the foreseeable future. However, no assurance can be given that this will be the case. If GasLog Ltd. is not entitled to this exemption under Section 883 for any taxable year, we would be subject to the 4% U.S. Federal income tax described above. The imposition of this taxation could have a negative effect on our business and would result in decreased earnings available for distribution to our shareholders. For a more detailed discussion, see "Material Tax Considerations—Taxation of the Company—U.S. Taxation of Shipping Income".

All statements in this prospectus supplement that are not statements of historical fact are "forward-looking statements" within the meaning of the United States Private Securities Litigation Reform Act of 1995. The disclosure and analysis set forth in this prospectus supplement includes assumptions, expectations, projections, intentions and beliefs about future events in a number of places, particularly in relation to our operations, cash flows, financial position, plans, strategies, business prospects, changes and trends in our business and the markets in which we operate. These statements are intended as "forward- looking statements". In some cases, predictive, future-tense or forward-looking words such as "believe", "intend", "anticipate", "estimate", "project", "forecast", "plan", "potential", "may", "should", "could" and "expect" and similar expressions are intended to identify forward-looking statements, but are not the exclusive means of identifying such statements. In addition, we and our representatives may from time to time make other oral or written statements which are forward-looking statements, including in our periodic reports that we file with the SEC, other information sent to our security holders and other written materials. We caution that these and other forward-looking statements included in this prospectus supplement represent our estimates and assumptions only as of the date of this prospectus supplement or the date on which such oral or written statements are made, as applicable, about factors that are beyond our ability to control or predict, and are not intended to give any assurance as to future results. Any of these factors or a combination of these factors could materially affect future results of operations and the ultimate accuracy of the forward-looking statements. Accordingly, you should not unduly rely on any forward-looking statements.

Factors that might cause future results and outcomes to differ include, but are not limited to, the following:

We undertake no obligation to update or revise any forward-looking statements contained in this prospectus supplement, whether as a result of new information, future events, a change in our views or expectations or otherwise, except as required by applicable law. New factors emerge from time to time, and it is not possible for us to predict all of these factors. Further, we cannot assess the impact of each such factor on our business or the extent to which any factor, or combination of factors, may cause actual results to be materially different from those contained in any forward-looking statement. We make no prediction or statement about the performance of the Notes.

We estimate that the net proceeds from this offering, after deducting underwriting discounts and estimated expenses payable by us, will be approximately $ million. We plan to use the proceeds of this offering to partially fund the company's committed growth capital program and for general corporate purposes, including working capital.

The following table sets forth our consolidated capitalization as of March 31, 2019 on an:

Other than these adjustments, there has been no material change in our capitalization from debt or equity issuances, re-capitalizations or special dividends between March 31, 2019, and the date of this prospectus supplement.

This table is derived from and should be read together with our consolidated financial statements, the related notes and other financial information contained in our Annual Report on Form 20-F for

the fiscal year ended December 31, 2018, which is incorporated by reference in this prospectus supplement.

	As of March 31, 2019

	Actual			As Adjusted			As Further Adjusted
	(in thousands of U.S. dollars)
Debt:⁽¹⁾
Borrowings, current portion⁽²⁾	$	172,686		$	159,062		$
Borrowings, non-current portion⁽²⁾		2,748,035			2,823,035
Lease liability, current portion		8,959			8,539
Lease liability, non-current portion		203,100			203,100
Additional Notes offered hereby		—			—

Total debt		3,132,780			3,193,736

Equity:
Preference shares⁽³⁾		46			46
Share capital⁽³⁾		810			810
Contributed surplus		835,931			835,931
Reserves		18,889			14,327
Treasury shares⁽³⁾		(7,018	)		(2,456	)
Retained earnings		1,882			1,882
Non-controlling interest		1,093,729			1,070,534

Total equity		1,944,269			1,921,074

Total capitalization	$	5,077,049		$	5,114,810		$

⁽¹⁾: Our indebtedness, other than the Existing Notes and our NOK 2021 Bonds (as defined in the section "Description of Other Indebtedness"), is secured by mortgages on our owned ships and is guaranteed by the Company or a combination of the Company and GasLog Partners, in the case of the Partnership's indebtedness. The Existing Notes (the carrying amount of which, net of unamortized financing costs as of March 31, 2019, is $246.97 million) are unsecured. The NOK 2021 Bonds (the carrying amount of which, net of unamortized financing costs as of March 31, 2019, is $86.03 million) are unsecured.
⁽²⁾: Borrowings presented at March 31, 2019, are shown net of $55.18 million of loan issuance costs that are being amortized over the term of the respective borrowings. Amortization of loan issuance costs for the period March 31, 2019 to May 13, 2019, is not included on an as adjusted and on an as further adjusted basis.
⁽³⁾: Does not include any shares that may be issued under the Company's 2013 Omnibus Incentive Compensation Plan. At March 31, 2019, our share capital consisted of (a) 80,649,135 issued and outstanding common shares, 343,991 treasury shares issued and 4,600,000 Preference Shares issued and outstanding and (b) 80,854,957 issued and outstanding common shares, 138,169 treasury shares issued and 4,600,000 Preference Shares issued and outstanding, as adjusted.

On October 16, 2015, GAS-eleven Ltd., GAS-twelve Ltd., GAS-thirteen Ltd., GAS-fourteen Ltd., GAS-twenty two Ltd., GAS-twenty three Ltd., GAS-twenty four Ltd. and GAS-twenty five Ltd. entered into a debt financing agreement (the "Newbuilding Facility") with 14 international banks for $1,311.36 million to partially finance the delivery of the eight newbuildings expected to be delivered in 2016, 2018 and 2019. The financing is backed by the Export Import Bank of Korea ("KEXIM") and the Korea Trade Insurance Corporation ("K-Sure"), who are either directly lending or providing cover for over 60% of the facility.

The loan agreement provides for four tranches of $412.46 million, $201.09 million, $206.12 million and $491.69 million. The facility is also sub-divided into eight loans, one loan per newbuilding vessel, to be provided for each of the vessels on a pro rata basis under each of the four tranches. Each drawing under the first three tranches shall be repaid in 24 consecutive semi-annual equal installments commencing six months after the actual delivery of the relevant vessel according to a 12-year profile. Each drawing under the fourth tranche shall be repaid in 20 consecutive semi-annual equal installments commencing six months after the actual delivery of the relevant vessel according to a 20-year profile, with a balloon payment together with the final installment. On March 22, 2016 and June 24, 2016, $162.97 million was drawn down on each date with respect to the deliveries of the GasLog Greece and the GasLog Glasgow, on September 26, 2016 and October 25, 2016, $160.70 million was drawn down on each date with respect to the deliveries of the GasLog Geneva and the GasLog Gibraltar, on January 2, 2018 and March 14, 2018, $166.21 million was drawn down on each date with respect to the deliveries of the GasLog Houston and the GasLog Hong Kong, on March 23, 2018, $165.81 million was drawn down with respect to the delivery of the GasLog Genoa, while on March 11, 2019, $165.81 million was drawn down with respect to the delivery of the GasLog Gladstone. The aggregate balance outstanding under the loan facility as of March 31, 2019 was $1,161.35 million. Amounts drawn bear interest at LIBOR plus a margin.

On February 18, 2016, GAS-eighteen Ltd., GAS-nineteen Ltd., GAS-twenty Ltd., GAS-twenty one Ltd. and GAS-twenty seven Ltd. entered into a credit facility (the "Five Vessel Refinancing") to refinance the debt maturities that were scheduled to become due in 2016 and 2017. The Five Vessel Refinancing is currently comprised of a five-year facility of up to $396.50 million. The vessels covered by the Five Vessel Refinancing are the GasLog Partners-owned Methane Alison Victoria, Methane Shirley Elisabeth, Methane Heather Sally and Methane Becki Anne and the GasLog-owned Methane Lydon Volney.

On April 5, 2016, $395.45 million of the Five Vessel Refinancing was drawn down to partially refinance $464.25 million of the outstanding debt of GAS-eighteen Ltd., GAS-nineteen Ltd., GAS-twenty Ltd., GAS-twenty one Ltd. and GAS-twenty seven Ltd. The balance of $68.80 million was paid from available cash. Following the decrease in the aggregate available amount by $1.30 million, the Five Vessel Refinancing provides for four advances of $72.29 million each and a fifth advance of $106.30 million. The first four advances shall be repaid in 20 quarterly equal installments commencing three months after the relevant drawdown dates while the fifth advance shall be repaid in 17 quarterly equal installments commencing 12 months after the relevant drawdown date, with a balloon payment together with the final installments.

The aggregate balance outstanding under the Five Vessel Refinancing as of March 31, 2019 was $313.51 million. Amounts drawn bear interest at LIBOR plus a margin.

On July 19, 2016, GAS-one Ltd., GAS-two Ltd., GAS-six Ltd., GAS-seven Ltd., GAS-eight Ltd., GAS-nine Ltd., GAS-ten Ltd. and GAS-fifteen Ltd. entered into a credit agreement (the "Legacy Facility Refinancing") to refinance the existing indebtedness on eight of GasLog's on-the-water vessels of up to $1,050.00 million, extending the maturities of six existing credit facilities to 2021. The vessels covered by the Legacy Facility Refinancing are the GasLog Savannah, the GasLog Singapore, the GasLog Skagen, the GasLog Seattle, the Solaris, the GasLog Saratoga, the GasLog Salem and the GasLog Chelsea.

The Legacy Facility Refinancing is comprised of a five-year term loan facility of up to $950.00 million and a revolving credit facility of up to $100.00 million. On July 25, 2016, the available amount of $950.00 million under the term loan facility was drawn to refinance the aggregate existing indebtedness of $948.26 million of GAS-one Ltd., GAS-two Ltd., GAS-six Ltd., GAS-seven Ltd., GAS-eight Ltd., GAS-nine Ltd., GAS-ten Ltd. and GAS-fifteen Ltd. Amounts drawn bear interest at LIBOR plus a margin. The balance outstanding as of March 31, 2019 of $804.17 million under the term loan facility shall be repaid in four semi-annual installments of $29.17 million each and a balloon repayment of $687.50 million five years after drawdown. The revolving credit facility as of March 31, 2019 was undrawn while the available amount of $100.00 million can be drawn and repaid at any time until January 2021 and July 2021, respectively.

On February 20, 2019, GasLog Partners entered into a credit agreement (the "2019 GasLog Partners Facility") to refinance the existing indebtedness due in November 2019 on five of its vessels (the "Existing Partnership Facility"), of up to $450.0 million. The vessels covered by the 2019 GasLog Partners Facility are the GasLog Shanghai, the GasLog Santiago, the GasLog Sydney, the Methane Rita Andrea and the Methane Jane Elizabeth.

The 2019 GasLog Partners Facility provides for an amortizing revolving credit facility which can be repaid and redrawn at any time for a period of five years. The total available facility amount will be reduced on a quarterly basis, with a final balloon amount payable concurrently with the last quarterly installment, if any, in February 2024. On March 6, 2019, the Partnership drew down $360.0 million under the 2019 GasLog Partners Facility, out of which $354.4 million was used to refinance the Existing Partnership Facility. Amounts drawn bear interest at LIBOR plus a margin.

The obligations under the aforementioned facilities are secured by a first priority mortgage over the vessels, a pledge of the share capital of the respective vessel owning companies and a first priority assignment of earnings related to the vessels (excluding the vessels participating in the Cool Pool), including charter revenue, management revenue and any insurance and requisition compensation. Obligations under the Newbuilding Facility are guaranteed by GasLog, the Partnership and GasLog Partners Holdings LLC for up to the value of the commitments relating to the GasLog Greece, the GasLog Glasgow, the GasLog Geneva and the GasLog Gibraltar and by GasLog Carriers Ltd. for up to the value of the commitments on the remaining vessels, obligations under the Five Vessel Refinancing are guaranteed by GasLog, by the Partnership and GasLog Partners Holdings LLC for up to the value of the commitments relating to the Methane Alison Victoria, Methane Shirley Elisabeth, Methane Heather Sally and the Methane Becki Anne and by GasLog Carriers Ltd. for up to the value of the commitments on the remaining vessel, obligations under the Legacy Facility Refinancing are guaranteed by GasLog, by the Partnership and GasLog Partners Holdings LLC for up to the value of the commitments relating to the GasLog Seattle and the Solaris and by GasLog Carriers Ltd. for up to the value of the commitments on the remaining vessels, while obligations under the 2019 GasLog Partners Facility are

guaranteed by the Partnership and GasLog Partners Holdings LLC. The facilities include customary respective covenants, and among other restrictions the facilities include a fair market value covenant pursuant to which the majority lenders may request additional security under the facilities if the aggregate fair market value of the collateral vessels (without taking into account any charter arrangements) were to fall below 120% of the aggregate outstanding principal balance (with respect to each individual vessel in the Newbuilding Facility, below 115% of the outstanding principal balance of that vessel for the first two years after each drawdown and below 120% at any time thereafter).

On June 27, 2016, GasLog issued senior unsecured bonds of NOK 750.0 million (or $90.2 million based on the exchange rate on June 27, 2016) ("NOK 2021 Bonds") that will mature on June 27, 2021. The total outstanding balance of the NOK 2021 Bonds amounts to NOK 750.0 million. The NOK 2021 Bonds bear interest at NIBOR plus margin. Interest payments shall be made in arrears on a quarterly basis. GasLog may redeem the bonds in whole or in part as follows: (a) with settlement date at any time from June 27, 2019 to but not including June 27, 2020 at 104.0% of par plus accrued interest on redeemed amount, (b) with settlement date at any time from June 27, 2020 to but not including December 27, 2020 at 102.5% of par plus accrued interest on redeemed amount, and (c) with settlement date at any time from December 27, 2020 to but not including the maturity date at 101.0% of par plus accrued interests on redeemed amount.

Compliance with our bonds' covenants is required at all times and we were in compliance with the respective financial covenants as of May 13, 2019.

The carrying amount under the NOK 2021 Bonds, net of unamortized financing costs, as of March 31, 2019 was $86.03 million, while its fair value was $91.0 million based on a USD/NOK exchange rate of 0.1158 as of March 31, 2019.

On March 22, 2017, GasLog closed a public offering of the Existing Notes. The carrying amount under the Existing Notes, net of unamortized financing costs as of March 31, 2019 was $246.97 million.

Compliance with the Notes' covenants is required at all times and we were in compliance with the respective financial covenants as of May 13, 2019.

The Additional Notes being offered hereby will be a further issuance of, form a single series with and have the same terms as, the Existing Notes. The Additional Notes offered hereby will be designated by the same CUSIP number and trade interchangeably with the Existing Notes.

The following description is only a summary of certain provisions of the Notes and the Indenture. You should read those documents in their entirety because they, and not this description, define your rights as holders of the Notes. The following summary does not purport to be complete and is subject to, and is qualified in its entirety by reference to, the Trust Indenture Act of 1939, as amended (or the TIA), and to all of the provisions of the Indenture and those terms made a part of the Indenture by reference to the TIA. Unless the context requires otherwise, all references to "we", "us", and "our" in this section refer solely to GasLog Ltd., the issuer of the Notes, and not to any of its subsidiaries.

The following description of the particular terms of the Additional Notes offered hereby supplements the "Description of Debt Securities" set forth in the accompanying prospectus.

The Additional Notes offered by this prospectus supplement will be issued under the Indenture dated as of March 22, 2017 (or the Base Indenture), between the Issuer and American Stock Transfer & Trust Company, LLC, as trustee (or the Trustee), as supplemented by the First Supplemental Indenture dated as of March 22, 2017, between the Issuer and the Trustee (or the Supplemental Indenture and, together with the Base Indenture, the Indenture).

The $75.0 million aggregate principal amount of Additional Notes being offered hereby will be a further issuance of, form a single series with and have the same terms as, the $250.0 million aggregate principal amount of 8.875% Senior Notes due March 22, 2022 issued on March 22, 2017. The Additional Notes offered hereby will be designated by the same CUSIP number and trade interchangeably with the Existing Notes. Immediately upon settlement, the aggregate principal amount of the Notes outstanding will increase to $325.0 million. The Notes will mature on March 22, 2022.

The Indenture does not limit the amount of debt securities that the Issuer may issue under the Indenture and provides that debt securities may be issued from time to time in one or more series. The Issuer may from time to time, without giving notice to or seeking the consent of the holders of the Notes, issue debt securities having the same interest rate, maturity and other terms (except for the issue date, the public offering price and the first interest payment date) as, and ranking equally and ratably with, the Notes. Any additional debt securities having such similar terms, together with the Notes, will constitute a single series of debt securities under the Indenture, including for purposes of voting and redemptions, and any additional debt securities issued as part of the same series as the Notes will be fungible with the Notes for United States federal income tax purposes or will be issued under a separate CUSIP number. No such additional debt securities may be issued if an Event of Default has occurred and is continuing with respect to the Notes. For the avoidance of doubt, so long as no default or Event of Default hereunder would result therefrom, nothing contained in the Indenture prohibits the Issuer from entering into commercial loans or bank debt, whether secured or unsecured, including without limitation, such debt that may be syndicated.

Other than as described under "—Certain Covenants", the Indenture and the terms of the Notes do not contain any covenants restricting the operation of our business, our ability to pay dividends, our ability to incur debt or grant liens on our assets or that are designed to afford holders of the Notes protection in a highly leveraged or other transaction involving us that may adversely affect holders of the Notes.

The Notes will mature on March 22, 2022 and will bear interest at a rate of 8.875% per annum. Interest on the Additional Notes will accrue from March 30, 2019. The Issuer will make interest payments on the Additional Notes quarterly in arrears on March 30, June 30, September 30 and December 30 of each year, beginning on June 30, 2019, to holders of record at the close of business on March 15, June 15, September 15 or December 15 (whether or not that date is a business day), as the

case may be, immediately preceding such interest payment date, and on the maturity date. Interest on the Notes will be computed on the basis of a 360-day year composed of twelve 30-day months. Accrued interest on the Additional Notes from March 30, 2019, totaling $ , must be paid by purchasers of the Additional Notes.

If any interest payment date would otherwise be a day that is not a business day, that interest payment date will be postponed to the next date that is a business day. If the maturity date of the Notes falls on a day that is not a business day, the related payment of principal and interest will be made on the next business day as if it were made on the date such payment was due, and no interest will accrue on the amounts so payable for the period from and after such date to the next business day.

The Notes will be issued only in fully registered form without coupons and in minimum denominations of $1,000 and integral multiples of $1,000 in excess thereof. The Notes will be represented by one or more global securities registered in the name of a nominee of DTC. Except as described under "—Book-entry System; Delivery and Form", the Notes will not be issuable in certificated form.

The Notes are not listed, and we do not currently intend to list the Notes, on any securities exchange or to seek approval for their quotation through any automated quotation system. We cannot assure you that an active public market for the Notes will develop. The absence of an active public trading market could have an adverse effect on the liquidity and value of the Notes.

The Notes are expected to trade at a price that takes into account the value, if any, of accrued but unpaid interest; thus, purchasers will not pay and sellers will not receive accrued and unpaid interest with respect to the Notes that is not included in the trading price thereof. Any portion of the trading price of a Note received that is attributable to accrued interest will be treated as ordinary interest income for federal income tax purposes and will not be treated as part of the amount realized for purposes of determining gain or loss on the disposition of the Note.

The Notes will be our unsubordinated unsecured obligations and will rank equally in right of payment with all our existing and future unsubordinated unsecured indebtedness.

The Notes will rank senior in right of payment to all of our existing and future subordinated indebtedness.

The Notes will effectively rank junior to our current and any future secured indebtedness incurred by us, to the extent of the value of the assets securing such indebtedness. Assuming we had completed this offering on March 31, 2019, after giving effect to the issuance of our Notes and assuming we held all of the net proceeds of the offering as cash, we and our subsidiaries would have had an aggregate of approximately $ billion of debt outstanding. Of such amount, approximately $2.6 billion would have been secured bank debt and $0.2 billion would have been finance leases, all of which is debt of our subsidiaries. Please read "Risk Factors—The Notes will be unsecured obligations and will be effectively subordinated to our secured debt."

The Notes will be obligations of the Issuer and will not be guaranteed by any of our subsidiaries. Accordingly, the Notes will effectively rank junior to all liabilities of our subsidiaries (excluding any amounts owed by such subsidiaries to us). We derive substantially all of our operating income and cash flow from our investments in our subsidiaries. Claims of creditors of our subsidiaries generally will have priority with respect to the assets and earnings of such subsidiaries over the claims of our creditors,

including holders of the Notes. As a result, the Notes will be effectively subordinated to creditors, including trade creditors and preferred shareholders or unitholders, if any, other than us, of our subsidiaries. Please read "Risk Factors—The Notes will be unsecured obligations and will be effectively subordinated to our secured debt."

All payments made by or on behalf of the Issuer under or with respect to the Notes will be made free and clear of and without withholding or deduction for, or on account of, any present or future tax, duty, levy, impost, assessment or other governmental charge (including penalties, interest and other liabilities related thereto) (or Taxes) unless the withholding or deduction of such Taxes is then required by law. If any deduction or withholding for, or on account of, any Taxes imposed or levied by or on behalf of the government of Bermuda or any political subdivision or any authority or agency therein or thereof having power to tax, or any other jurisdiction in which the Issuer (including any successor entity) is organized or is otherwise resident for tax purposes, or any jurisdiction from or through which payment is made (including, without limitation, the jurisdiction of each paying agent) (each, a Specified Tax Jurisdiction), will at any time be required to be made from any payments made under or with respect to the Notes, the Issuer will pay such additional amounts (or the Additional Amounts) as may be necessary so that the net amount received in respect of such payments by a holder (including Additional Amounts) after such withholding or deduction will not be less than the amount such holder would have received if such Taxes had not been withheld or deducted; provided, however, that the foregoing obligation to pay Additional Amounts does not apply to:

If the Issuer becomes aware that it will be obligated to pay Additional Amounts with respect to any payment under or with respect to the Notes, the Issuer will deliver to the Trustee and paying agent at least 30 days prior to the date of that payment (unless the obligation to pay Additional Amounts arises after the 30th day prior to that payment date, in which case the Issuer will notify the Trustee and paying agent promptly thereafter but in no event later than two business days prior to the date of payment) an Officer's Certificate stating the fact that Additional Amounts will be payable and the amount so payable. The Officer's Certificate must also set forth any other information necessary to enable the paying agent to pay Additional Amounts to holders on the relevant payment date. The Trustee and paying agent will be entitled to rely solely on such Officer's Certificate as conclusive proof that such payments are necessary. The Issuer will provide the Trustee and paying agent with documentation satisfactory to the Trustee and paying agent evidencing the payment of Additional Amounts.

The Issuer will make all withholdings and deductions required by law and will remit the full amount deducted or withheld to the relevant governmental authority on a timely basis in accordance with applicable law. As soon as practicable, the Issuer will provide the Trustee and paying agent with an official receipt or, if official receipts are not obtainable, other documentation satisfactory to the Trustee and paying agent evidencing the payment of the Taxes so withheld or deducted. Upon request, copies of those receipts or other documentation, as the case may be, will be made available by the Trustee and paying agent to the holders of the Notes.

Whenever in the Indenture there is referenced, in any context, the payment of amounts based upon the principal amount of the Notes or of principal, interest or any other amount payable under, or with respect to, the Notes, such reference will be deemed to include payment of Additional Amounts as described under this heading to the extent that, in such context, Additional Amounts are, were or would be payable in respect thereof.

The Issuer will pay any present or future stamp, court, issue, registration, value added, court or documentary taxes or any other excise or property taxes, charges or similar levies that arise in any Specified Tax Jurisdiction from the execution, delivery, enforcement or registration of the Notes, the Indenture or any other document or instrument in relation thereof, or the receipt of any payments with respect to the Notes, other than, for the avoidance of doubt, any Transfer Taxes, as defined below

in "—Transfer and Exchange" (each such tax, a Note Issuance Tax), and the Issuer will indemnify the holders for any such Note Issuance Taxes paid by such holders.

The obligations described under this heading will survive any termination, defeasance or discharge of the Indenture and will apply mutatis mutandis to any jurisdiction in which any successor person to the Issuer is organized or any political subdivision or authority or agency thereof or therein.

The Issuer may redeem the Notes, at its option, at any time in whole but not in part, upon not less than 30 nor more than 60 days' notice (which notice will be irrevocable) by the Issuer, at a redemption price equal to 100% of the outstanding principal amount of Notes, plus accrued and unpaid interest (if any) to, but excluding, the applicable redemption date and all Additional Amounts (if any) then due and which will become due on the applicable redemption date (subject to the right of holders of record on the relevant record date to receive interest due on the relevant interest payment date and Additional Amounts (if any) in respect thereof), in the event that the Issuer determines in good faith that the Issuer has become or would become obligated to pay, on the next date on which any amount would be payable with respect to the Notes, Additional Amounts and such obligation cannot be avoided by taking reasonable measures available to the Issuer (including making payment through a paying agent located in another jurisdiction), as a result of:

Notwithstanding the foregoing, no such notice of redemption may be given earlier than 60 days prior to the earliest date on which the Issuer would be obligated to pay Additional Amounts if a payment in respect of the Notes were then due. Before the Issuer publishes, mails or delivers notice of redemption of the Notes as described above, the Issuer will deliver to the Trustee and paying agent (a) an Officer's Certificate stating that the Issuer is entitled to effect such redemption and setting forth a statement of facts showing that the conditions precedent to the right of the Issuer to so redeem have occurred and (b) an opinion of independent legal counsel of recognized standing satisfactory to the Trustee and paying agent that the Issuer has or will become obligated to pay Additional Amounts as a result of the circumstances referred to in clause (1) or (2) of the preceding paragraph.

The Trustee and paying agent will accept and will be entitled to conclusively rely upon the Officer's Certificate and opinion of counsel sufficient evidence of the satisfaction of the conditions precedent described above, in which case they will be conclusive and binding on the holders.

The Issuer may redeem the Notes, in whole or in part, at any time and from time to time at a redemption price equal to the greater of:

plus accrued and unpaid interest, if any, to but excluding the redemption date (subject to the rights of holders of record on the relevant record date to receive interest due on the relevant interest payment date).

Any notice to holders of Notes of such a redemption needs to include the appropriate calculation (such calculation to be made by the Issuer) of the redemption price, but does not need to include the redemption price itself. The actual redemption price, calculated as described above, must be set forth in an Officers' Certificate delivered to the Trustee no later than two business days prior to the redemption date.

Unless the Issuer defaults in the payment of the redemption price, interest will cease to accrue on the Notes or portions thereof called for redemption on the applicable redemption date.

"Comparable Treasury Issue" means the United States Treasury security selected by an Independent Investment Banker as having a maturity comparable to March 22, 2022 that would be utilized, at the time of selection and in accordance with customary financial practice, in pricing new issues of corporate debt securities of comparable maturity.

"Comparable Treasury Price" means, with respect to any redemption date (a) the average of the bid and asked prices for the Comparable Treasury Issue (expressed in each case as a percentage of its principal amount) on the third business day preceding such redemption date, as set forth in the most recently published statistical release designated "H.15(519)" (or any successor release) published by the Board of Governors of the Federal Reserve System and which establishes yields on actively traded United States treasury securities adjusted to constant maturity under the caption "Treasury Constant Maturities", or (b) if such release (or any successor release) is not published and does not contain such prices on such business day, the average of the Reference Treasury Dealer Quotations for such redemption date.

"Independent Investment Banker" means one of the Reference Treasury Dealers appointed by the Issuer.

"Reference Treasury Dealer" means each of four nationally recognized investment banking firms selected by the Company that are primary U.S. Government security dealers in New York City.

"Reference Treasury Dealer Quotations" means, with respect to each Reference Treasury Dealer and any redemption date, the average, as determined by the Independent Investment Banker, of the bid and asked prices for the Comparable Treasury Issue (expressed in each case as a percentage of its principal amount) quoted in writing to the Independent Investment Banker by such Reference Treasury Dealer at 5:00 p.m. on the third business day preceding such redemption date.

"Treasury Rate" means, with respect to any redemption date, the rate per annum equal to the yield to maturity of the Comparable Treasury Issue, compounded quarterly, assuming a price for such Comparable Treasury Issue (expressed as a percentage of its principal amount) equal to the Comparable Treasury Price for such redemption date.

The Indenture includes the following restrictive covenants. Certain defined terms relevant to the covenants are set forth under "—Certain Definitions and Interpretations" below.

Compliance with clauses (12)-(16) in the preceding paragraph is measured on the last day of each of our fiscal quarters. Within 60 days after the end of the first three fiscal quarters each fiscal year and within 120 days after the end of each fiscal year (in each case subject to any extensions or waivers), the Issuer is required to deliver to the Trustee an Officer's Certificate confirming compliance with each of the covenants described above. Each such certificate will be made available to the holders of the Notes upon request to the Trustee. The Issuer shall mail, within 10 Business Days of the discovery thereof, to all holders of the Notes and Trustee, notice of any Default in compliance with the covenants described above.

For purposes of the foregoing provisions, the following definitions shall apply:

"Cash and Cash Equivalents" means cash on hand, deposits with banks which are repayable on demand, short term, highly liquid investments which are readily convertible into known amounts of cash with original maturities of six months or less that are subject to an insignificant risk of change in value, but exclude any cash that is specifically blocked and/or charged. For the avoidance of doubt, Cash and Cash Equivalents shall not be subject to any Encumbrances.

"Current Assets" means current assets of the Group as shown in the then most recent Financial Statements and Interim Accounts relevant to such period.

"Current Liabilities" means the current liabilities of the Group as shown in the then most recent Financial Statements and Interim Accounts relevant to such period.

"Current Portion of Loans" means the current portion of loans as shown in the then most recent Financial Statements of the Issuer.

"Debt Service" means, for any financial period of the Group, the sum to be the aggregate amount of: (i) scheduled amounts of principal; (ii) scheduled amounts of interest thereon (taking into account

any hedging contracts); and (iii) all other amounts in excess of $30,000,000 in aggregate which shall fall due and will be paid by the Group in such period as non-recurrent fees or upfront fees, costs and expenses, in respect of Total Indebtedness, as shown in the then most recent Financial Statements and Interim Accounts relevant to such period.

"Default" means an Event of Default or any event or circumstance specified under "—Events of Default" which would (with the giving of notice, lapse of time, determination of materiality or the fulfillment of any other applicable condition or any combination of the foregoing) be an Event of Default under the Indenture.

"EBITDA" means, in respect of any period, the consolidated profit on ordinary activities of the Group before taxation for such period; but: (a) adjusted to exclude Interest Receivable and Interest Payable and other similar income or costs to the extent not already excluded, (b) adjusted to exclude any gain or loss realized on the disposal of fixed assets (whether tangible or intangible), (c) after adding back depreciation and amortization charged which relates to such period, (d) adjusted to exclude any exceptional or extraordinary costs or income (e) after deducting any profit arising out of the release of any provisions against a liability or charge and adding back any provision relating to long term assets or contracts, and (f) adjusted to exclude any profit or loss due to mark-to-market of derivative agreements and non-cash currency gains or losses, as shown in the then most recent Financial Statement or Interim Account relevant to such period.

"Encumbrance" means any encumbrance, mortgage, pledge, lien, charge (whether fixed or floating), assignment by way of security, finance lease, sale and repurchase or sale and leaseback arrangement, sale of receivables on a recourse basis or security interest or any other agreement or arrangement having the effect of conferring security (provided that the foregoing shall not include a pledge of deposit accounts to the extent such pledge does not prevent withdrawal from such accounts at the time of the measurement date).

"Event of Default" means the occurrence of an event or circumstance specified under "—Events of Default".

"Financial Indebtedness" means any indebtedness for or in respect of: (i) moneys borrowed and debit balances at banks or other financial institutions; (ii) any amount raised by acceptance under any acceptance credit facility or dematerialized equivalent; (iii) any amount raised pursuant to any note purchase facility or the issue of bonds, notes, debentures, loan stock or any similar instrument; (iv) the amount of any liability in respect of any lease or hire purchase contract which would, in accordance with GAAP, be treated as a finance or capital lease; (v) receivables sold or discounted (other than any receivables to the extent they are sold on a non-recourse basis); (vi) any treasury transaction (and, when calculating the value of that treasury transaction, only the marked to market value shall be taken into account and/or, if any actual amount is due as a result of the termination or close out of a treasury transaction, that also shall be taken into account); (vii) any counter-indemnity obligation in respect of a guarantee, indemnity, bond, standby or documentary letter of credit or any other instrument issued by a bank or financial institution; (viii) any amount of liability under an advance or deferred purchase agreement if (a) one of the primary reasons behind entering into the agreement is to raise finance or (b) the agreement is in respect of the supply of assets or services and payment is due more than 180 days after the date of supply; (ix) any amount raised under any other transaction (including any forward sale or purchase agreement) having the commercial effect of a borrowing or otherwise classified as borrowings under GAAP; and (x) the amount of any liability in respect of any guarantee for any of the items referred to in paragraphs (i) to (ix) above.

"Financial Statements" means the audited consolidated annual financial statements of the Issuer for any financial year, prepared in accordance with GAAP, such accounts to include a profit and loss account, balance sheet and cash flow statement.

"GAAP" means International Financial Reporting Standards as issued by the International Accounting Standards Board as in effect from time to time.

"Group" means the Issuer and its Subsidiaries, and a "Group Company" means the Issuer or any of its Subsidiaries (as applicable).

"Interest" means, in respect to any specified Financial Indebtedness, all continuing regular or periodic costs, charges and expenses incurred in effecting, servicing or maintaining such Financial Indebtedness including (a) gross interest, commitment fees, discount and acceptance fees and guarantee, fronting and ancillary fees payable or incurred on any form of Financial Indebtedness and (b) arrangement fees or other upfront fees.

"Interest Payable" means, in respect of any period, the aggregate (calculated on a consolidated basis) of: (a) the amounts charged and posted (or estimated to be charged and posted) as a current accrual accrued during such period in respect of members of the Group by way of Interest on all Financial Indebtedness, but excluding any amount accruing as interest in-kind (and not as cash pay) to the extent capitalized as principal during such period and (b) net payments in relation to interest rate or currency hedging arrangements in respect of Financial Indebtedness (after deducting net income in relation to such interest rate or currency hedging arrangements), as shown in the then most recent Financial Statement or Interim Account relevant to such period.

"Interest Receivable" means, in respect of any period, the amount of interest accrued on cash balances of the Group (including the amount of interest accrued on the Accounts, to the extent that the account holder is entitled to receive such interest) during such period, as shown in the then most recent Financial Statement or Interim Account relevant to such period.

"Interim Accounts" means the unaudited consolidated quarterly financial statements of the Issuer for any quarter ending on a Quarter Date, drawn up according to GAAP.

"Market Adjusted Net Worth" means Total Market Adjusted Assets less Total Indebtedness.

"Material Adverse Effect" means a material adverse effect on: (a) the business, financial condition or operations of the Group taken as a whole, (b) the Issuer's ability to perform and comply with its obligations under the Indenture or the Notes; or (c) the validity or enforceability of the Indenture or the Notes.

"Material Group Company" means any Group Company whose total EBITDA represent at least 10% of the total consolidated EBITDA of the Group, always provided that the Issuer shall, if required, appoint Group Companies as "Material Group Companies" to procure that the Group Companies not being Material Group Companies shall in aggregate not exceed 20% of the consolidated EBITDA of the Group.

"MLP" means GasLog Partners L.P. (or another MLP established and controlled by the Issuer), a master limited partnership whose limited partnership units are traded on a regulated market place or a securities exchange established by a sponsor and which is managed and controlled by a General Partner with a number of limited partners (with customary limited voting rights in the MLP) as investors into which the profit is paid to the partners based on "available cash" with an aim of maximizing the MLP's distributions, but so that the actual distributions are based on the General Partner's discretion.

"Restricted Payment" means any dividend or other distribution (whether in cash, securities or other property) with respect to any units or shares of any class of capital stock of or other ownership interests in the Issuer or any Subsidiary (as the case may be), or any payment (whether in cash, securities or other property), including any sinking fund or similar deposit, on account of the purchase,

redemption, retirement, acquisition, cancellation or termination of any such shares of capital stock of or other ownership interests in the Issuer or any Subsidiary or any option, warrant or other right to acquire any such shares of capital stock of or other ownership interests in the Issuer or any Subsidiary other than any such payments that may be made by and between or among one or more of the Group Companies.

"Subsidiary" means an entity over which another entity or person has a determining influence due to (i) direct and indirect ownership of shares or other ownership interests, (ii) control of the general partner of any such other entity that is a limited partnership and/or (iii) agreement, understanding or other arrangement. An entity shall always be considered to be the subsidiary of another entity or person if such entity or person has such number of shares or ownership interests so as to represent the majority of the votes in the entity, or has the right to elect or dismiss a majority of the directors in the entity.

"Total Capitalization" means the sum of Total Indebtedness and Total Equity of the Group.

"Total Equity" means the Total Equity of the Group on a consolidated basis as determined in accordance with GAAP as shown in the then recent Financial Statements or Interim Accounts.

"Total Indebtedness" means the aggregate Financial Indebtedness (on a consolidated basis) of the Group as demonstrated by the Financial Statements and Interim Accounts.

"Total Market Adjusted Assets" means the Total Assets adjusted upwards or downwards, as the case may be, to reflect any difference between the book value of delivered vessels owned wholly or in part by the Group and mean valuations of such vessels provided to the Trustee in each compliance certificate conducted by two independent valuers.

"Wholly Owned Group Company" of any Person means a Group Company of such Person, all of the capital stock of which is owned by the Issuer or another Wholly Owned Group Company.

If a Change of Control (as defined below) occurs at any time, you will have the right, at your option, to require the Issuer to purchase for cash any or all of your Notes, or any portion of the principal amount thereof, that is equal to $1,000 or multiple of $1,000. The price the Issuer is required to pay (or the Change of Control Purchase Price) is equal to 101% of the principal amount of the Notes to be purchased plus accrued and unpaid interest to but excluding the Change of Control Purchase Date (unless the Change of Control Purchase Date is after a record date and on or prior to the interest payment date to which such record date relates, in which case the Issuer will instead pay the full amount of accrued and unpaid interest to the holder of record on such record date and the Change of Control Purchase Price will be equal to 101% of the principal amount of the Notes to be purchased). The "Change of Control Purchase Date" will be a date specified by us that is not less than 20 or more than 35 calendar days following the date of our Change of Control notice as described below. Any Notes purchased by the Issuer will be paid for in cash. A "Change of Control" will be deemed to have occurred at the time after the Notes are originally issued if:

As used above, "voting stock" applied to stock of any Person, means shares, interests, participations or other equivalents in the equity interest (however designated) in such Person having ordinary voting power for the election of a majority of the directors (or the equivalent) of such Person, other than shares, interests, participations or other equivalents having such power only by reason of the occurrence of a contingency.

"Permitted Holders" means collectively the Livanos family and the Radziwill family, including trusts and other entities formed for the benefit of these families.

On or before the 30th day after the occurrence of a Change of Control, we will provide to all holders of the Notes and the Trustee and paying agent a notice of the occurrence of the Change of Control and of the resulting purchase right. Such notice shall state, among other things:

Simultaneously with providing such notice, we will publish a notice containing this information in a newspaper of general circulation in The City of New York or publish the information on our website or through such other public medium as we may select.

To exercise the Change of Control purchase right, you must deliver, on or before the third business day (or as otherwise provided in the notice described above) immediately preceding the Change of Control Purchase Date, the Notes to be purchased, duly endorsed for transfer, together with a written purchase notice and the form entitled "Form of Change of Control Purchase Notice" on the reverse side of the Notes duly completed, to the paying agent. Your purchase notice must state:

You may withdraw any purchase notice (in whole or in part) by a written notice of withdrawal delivered to the paying agent prior to the close of business on the business day immediately preceding the Change of Control Purchase Date. The notice of withdrawal shall state:

The Issuer will be required to purchase the Notes on the Change of Control Purchase Date. You will receive payment of the Change of Control Purchase Price on the later of the Change of Control Purchase Date or the time of book-entry transfer or the delivery of the Notes. If the paying agent holds money or securities sufficient to pay the Change of Control Purchase Price of the Notes on the Change of Control Purchase Date, then:

In connection with any purchase offer pursuant to a Change of Control purchase notice, the Issuer will, if required, comply with the provisions of the tender offer rules under the Exchange Act that may then be applicable to them.

No Notes may be purchased at the option of holders thereof upon a Change of Control if the principal amount of the Notes has been accelerated, and such acceleration has not been rescinded, on or prior to the Change of Control Purchase Date.

The Change of Control purchase rights of the holders could discourage a potential acquirer of us. The Change of Control purchase feature, however, is not the result of management's knowledge of any specific effort to obtain control of us by any means or part of a plan by management to adopt a series of anti-takeover provisions.

The term Change of Control is limited to specified transactions and may not include other events that might adversely affect our financial condition. In addition, the requirement that the Issuer offers to purchase the Notes upon a Change of Control may not protect holders in the event of a highly leveraged transaction, reorganization, merger or similar transaction involving us.

The definition of Change of Control includes a phrase relating to the conveyance, transfer, sale, lease or disposition of "all or substantially all" of our consolidated assets. There is no precise, established definition of the phrase "substantially all" under applicable law. Accordingly, the ability of a holder of the Notes to require us to purchase its Notes as a result of the conveyance, transfer, sale, lease or other disposition of less than all of our assets may be uncertain.

If a Change of Control were to occur, the Issuer may not have enough funds to pay the Change of Control Purchase Price. The Issuer's ability to repurchase the Notes for cash may be limited by restrictions on its ability to obtain funds for such repurchase through dividends from its subsidiaries, the terms of its then-existing borrowing arrangements or otherwise. Please read "Risk Factors—We may not have the ability to raise the funds necessary to purchase the Notes as required upon a change of control, and our existing and future debt may contain limitations on our ability to purchase the Notes." If the Issuer fails to purchase the Notes when required following a Change of Control, the Issuer will be in Default under the Indenture. In addition, we have, and we may in the future incur, other indebtedness with similar change in control provisions permitting our holders to accelerate or to

require us to purchase their indebtedness upon the occurrence of similar events or on some specific dates.

The Issuer may not consolidate with or merge with or into, any other person or sell, assign, convey, transfer, lease its properties and assets as an entirety or substantially as an entirety to any person, unless:

Upon any consolidation, merger, sale, assignment, conveyance, transfer or lease of the properties and assets of the Issuer in accordance with the foregoing provisions, the successor person formed by such consolidation or into which the Issuer is merged or to which such sale, assignment, conveyance, transfer or lease is made shall succeed to, and be substituted for, and may exercise every right and power of, the Issuer under the Indenture; and thereafter, except in the case of a lease, the Issuer shall be released from all obligations and covenants under this Indenture and the Notes.

If an Event of Default, other than an Event of Default described in clause (7) above, occurs and is continuing, either the Trustee or the holders of at least 25% in aggregate principal amount of the outstanding Notes may declare the principal amount of the Notes to be due and payable immediately. If an Event of Default described in clause (8) above occurs, the principal amount of the Notes and accrued and unpaid interest, if any, will automatically become immediately due and payable.

After any such acceleration, but before a judgment or decree based on acceleration, the holders of a majority in aggregate principal amount of the Notes may, under certain circumstances, rescind and annul such acceleration if all Events of Default, other than the non-payment of accelerated principal and any premium, interest or Additional Amounts which have become due as a result of such acceleration, have been cured or waived.

Notwithstanding the foregoing, if we so elect, the sole remedy under the Indenture for an Event of Default relating to (i) our failure to file with the Trustee pursuant to Section 314(a)(1) of the Trust Indenture Act any documents or reports that we are required to file with the SEC pursuant to Section 13 or 15(d) of the Exchange Act, or (ii) the failure to comply with our reporting obligations to the Trustee and the SEC, as described under "—Reports" below will, after the occurrence of such an Event of Default, consist exclusively of the right to receive additional interest on the Notes at an annual rate equal to (a) 0.25% per annum of the outstanding principal amount of the Notes for each day during the 90-day period beginning on, and including, the date on which such Event of Default first occurs and on which such Event of Default is continuing; and (b) 0.50% per annum of the outstanding principal amount of the Notes for each day during the 90-day period beginning on, and including, the 91st day following, and including the date on which such Event of Default first occurs and on which such Event of Default is continuing. In the event we do not elect to pay the additional interest upon an Event of Default in accordance with this paragraph, the Notes will be subject to acceleration as provided above. This additional interest will be payable in arrears on the same dates and in the same manner as regular interest on the Notes. On the 181st day after such Event of Default first occurs (if not waived or cured prior to such 181st day), such additional interest will cease to accrue and the Notes will be subject to acceleration as provided above. The provisions of the Indenture described in this paragraph will not affect the rights of holders of Notes in the event of the occurrence of any other Events of Default.

In order to elect to pay additional interest as the sole remedy during the first 180 days after the occurrence of an Event of Default relating to the failure to comply with the reporting obligations in accordance with the immediately preceding paragraph, we must notify all holders of record of Notes and the Trustee and paying agent of such election on or before the close of business on the fifth business day prior to the date on which such Event of Default would otherwise occur. Upon our failure to timely give such notice or pay additional interest, the Notes will be immediately subject to acceleration as provided above.

The Trustee will not be obligated to exercise any of its rights or powers at the request of the holders unless the holders have offered to the Trustee indemnity or security satisfactory to it against any loss, liability or expense. Subject to the Indenture, applicable law and upon providing

indemnification satisfactory to the Trustee, the holders of a majority in aggregate principal amount of the outstanding Notes will have the right to direct the time, method and place of conducting any proceeding for any remedy available to the Trustee or exercising any trust or power conferred on the Trustee with respect to the Notes. The Indenture provides that in the event an Event of Default has occurred and is continuing, the Trustee will be required in the exercise of its powers to use the degree of care that a prudent person would use in the conduct of such person's own affairs. The Trustee, however, may refuse to follow any direction that conflicts with law or the Indenture or that the Trustee determines is unduly prejudicial to the rights of any other holder.

No holder will have any right to institute any proceeding, judicial or otherwise, with respect to or under the Indenture, or for the appointment of a receiver or a Trustee, or for any other remedy under the Indenture unless:

However, the above limitations do not apply to a suit instituted by a holder for the enforcement of payment of the principal of or interest on any Note on or after the applicable due date in accordance with the Indenture.

Generally, the holders of not less than a majority of the aggregate principal amount of outstanding Notes may waive any Default or Event of Default unless:

The Indenture provides that within 90 days after the Trustee receives written notice of a Default, the Trustee shall transmit by mail to all holders, notice of such Default hereunder, unless such Default shall have been cured or waived. Except in the case of a Default in the payment of principal of or interest on any note, the Trustee may withhold notice if and so long as the Trustee in good faith determines that withholding notice is in the best interest of the holders.

Each holder shall have the right to receive payment or delivery, as the case may be, of:

its Notes, on or after the respective due dates expressed or provided for in the Indenture, or to institute suit for the enforcement of any such payment or delivery, as the case may be, and such right to receive such payment or delivery, as the case may be, on or after such respective dates shall not be impaired or affected without the consent of such holder.

The Issuer and the Trustee may amend or supplement the Indenture with respect to the Notes with the consent (including consents obtained in connection with any tender offer or exchange offer) of the holders of a majority in aggregate principal amount of the outstanding Notes. In addition, the holders of a majority in aggregate principal amount of the outstanding Notes may waive the Issuer's compliance in any instance with any provision of the Indenture without notice to the other holders of Notes. However, no amendment, supplement or waiver may be made without the consent of each holder of outstanding Notes affected thereby if such amendment, supplement or waiver would:

The Issuer and the Trustee may amend or supplement the Indenture or the Notes without notice to, or the consent of, the holders of the Notes to:

The consent of the holders is not necessary under the Indenture to approve the particular form of any proposed amendment. It is sufficient if such consent approves the substance of the proposed amendment. After an amendment under the Indenture becomes effective, we are required to mail to the holders a notice briefly describing such amendment. However, the failure to give such notice to all the holders, or any defect in the notice, will not impair or affect the validity of the amendment.

The Issuer may satisfy and discharge its obligations under the Indenture by delivering to the registrar for cancellation all outstanding Notes or irrevocably depositing with the Trustee or delivering to the holders, as applicable, after all outstanding Notes have become due and payable, or will become due and payable at their stated maturity within one year, or have been called for redemption or are to be called for redemption within one year, cash sufficient to pay and discharge the entire indebtedness on all of the outstanding Notes and all other sums payable under the Indenture by the Issuer. Such discharge is subject to terms contained in the Indenture.

If the Issuer satisfies and discharges its obligations under the Indenture, the Issuer will be released from its obligations in the provisions described under "—Change of Control Permits Holders to Require the Issuer to Purchase Notes".

The Issuer may terminate at any time all its obligations with respect to the Notes and the Indenture, which we refer to as "legal defeasance", except for certain obligations, including those respecting the defeasance trust and obligations to register the transfer or exchange of the Notes, to replace mutilated, destroyed, lost or stolen Notes and to maintain a registrar and paying agent in respect of the Notes. The Issuer may also terminate at any time the Issuer's obligations with respect to the Notes under the covenants described under "—Change of Control Permits Holders to Require the Issuer to Purchase Notes", "—Certain Covenants" and "—Reports", and the operation of certain Events of Default, which we refer to as "covenant defeasance". The Issuer may exercise the legal defeasance option notwithstanding its prior exercise of the covenant defeasance option.

If the Issuer exercises its legal defeasance option with respect to the Notes, payment of the Notes may not be accelerated because of an Event of Default with respect thereto. If the Issuer exercises the covenant defeasance option with respect to the Notes, payment of the Notes may not be accelerated because of an Event of Default specified in clause (4), clause (5) (with respect to the covenants described under "—Certain Covenants" or "—Reports"), clause (6) or clause (7).

The legal defeasance option or the covenant defeasance option with respect to the Notes may be exercised only if:

If the Issuer defeases its obligations under the Indenture, the Issuer will be released from its obligations in the provisions described under "—Change of Control Permits Holders to Require the Issuer to Purchase Notes".

We will maintain an office in New York City where the Notes may be presented for registration of transfer or exchange. This office will initially be an office or agency of the Trustee. No service charge will be imposed by us, the Trustee or the registrar for any registration of transfer or exchange of Notes, but any tax or similar governmental charge required by law or permitted by the Indenture because a holder requests any Notes to be issued in a name other than such holder's name will be paid by such holder (each such tax or similar governmental charge, a Transfer Tax). We are not required to transfer or exchange any Note surrendered for purchase except for any portion of that Note not being purchased.

Payments in respect of the principal and interest on global notes registered in the name of DTC or its nominee will be payable to DTC or its nominee, as the case may be, in its capacity as the registered holder under the Indenture. In the case of certificated Notes, payments will be made in U.S. dollars at the office of the Trustee or, at our option, by wire transfer or check mailed to the holder's registered address. The Issuer will make any required interest payments to the person in whose name each note is registered at the close of business on the record date for the interest payment.

The Trustee will be designated as the Issuer's paying agent for payments on the Notes. We may at any time designate additional paying agents or rescind the designation of any paying agent or approve a change in the office through which any paying agent acts.

Subject to the requirements of any applicable abandoned property laws, the Trustee and paying agent shall pay to us upon written request any money held by them for payments on the Notes that remain unclaimed for two years after the date upon which that payment has become due. After payment to us, holders entitled to the money must look to the Issuer for payment. In that case, all liability of the Trustee or paying agent with respect to that money will cease.

The registrar and paying agent (if other than the Trustee) will forward to the Trustee any Notes surrendered to them by holders for transfer, exchange or payment. All Notes delivered to the Trustee shall be cancelled promptly by the Trustee in the manner provided in the Indenture and may not be reissued or resold. No Notes shall be authenticated in exchange for any Notes cancelled, except as provided in the Indenture.

We may, to the extent permitted by law, and directly or indirectly (regardless of whether such Notes are surrendered to us), purchase Notes in the open market or by tender offer at any price or by private agreement.

So long as any Notes are outstanding, we will (i) file with the SEC within the time periods prescribed by its rules and regulations and applicable to us and (ii) furnish to the Trustee and the holders of the Notes within 15 days after the date on which we would be required to file the same with the SEC pursuant to its rules and regulations (giving effect to any grace period provided by Rule 12b-25 under the Exchange Act):

We shall not be required to file any report or other information with the SEC if the SEC does not permit such filing, although such reports will be required to be furnished to the Trustee. Documents filed by us with the SEC via the EDGAR system will be deemed to have been furnished to the Trustee and the holders of the Notes as of the time such documents are filed via EDGAR; provided, however, that the Trustee shall have no obligation whatsoever to determine whether or not such filing has occurred.

We will replace mutilated, destroyed, stolen or lost Notes at the expense of the holder upon delivery to the Trustee of the mutilated Notes, or evidence of the loss, theft or destruction of the Notes satisfactory to us and the Trustee. In the case of a lost, stolen or destroyed note, indemnity satisfactory to the Trustee and us may be required at the expense of the holder of such note before a replacement note will be issued.

Except as otherwise described herein, notice to registered holders of the Notes will be given to the addresses as they appear in the security register. Notices will be deemed to have been given on the date of such mailing or electronic delivery. Whenever a notice is required to be given by us, such notice

may be given by the Trustee on our behalf (and we will make any notice we are required to give to holders available on our website).

The Indenture and the Notes will be governed by and construed in accordance with the laws of the State of New York without regard to conflicts of laws.

The Trustee, in its individual and any other capacity, may make loans to, accept deposits from, and perform services for the Issuer as if it were not the Trustee; however, if it acquires any conflicting interest, it must eliminate such conflict within 90 days, apply to the SEC for permission to continue or resign.

The Indenture provides that in case an Event of Default shall occur and be continuing (which shall not be cured), the Trustee will be required, in the exercise of its power, to use the degree of care of a prudent person in the conduct of such person's own affairs. Subject to such provisions, the Trustee will be under no obligation to exercise any of its rights or powers under the Indenture at the request of any holder of the Notes, unless such holder shall have offered to the Trustee security and indemnity satisfactory to it against any loss, liability or expense.

American Stock Transfer & Trust Company, LLC is the Trustee under the Indenture. Initially, the Trustee will also act as the paying agent, registrar and custodian for the Notes.

The Issuer will issue the Notes in the form of one or more global notes in definitive, fully registered, book-entry form.

The global notes will be deposited with or on behalf of DTC and registered in the name of Cede & Co., as nominee of DTC.

Beneficial interests in the global notes will be represented through book-entry accounts of financial institutions acting on behalf of beneficial owners as direct and indirect participants in DTC. Investors may hold interests in the global notes through either DTC (in the United States), Clearstream Banking, société anonyme, Luxembourg, which we refer to as Clearstream, or Euroclear Bank S.A./N.V., as operator of the Euroclear System, which we refer to as Euroclear, in Europe, either directly if they are participants in such systems or indirectly through organizations that are participants in such systems. Clearstream and Euroclear will hold interests on behalf of their participants through customers' securities accounts in Clearstream's and Euroclear's names on the books of their U.S. depositaries, which in turn will hold such interests in customers' securities accounts in the U.S. depositaries' names on the books of DTC.

We have obtained the information in this section concerning DTC, Clearstream and Euroclear and the book-entry system and procedures from sources that we believe to be reliable, but we take no responsibility for the accuracy of this information.

We understand that Clearstream is incorporated under the laws of Luxembourg as a professional depositary. Clearstream holds securities for its customers and facilitates the clearance and settlement of securities transactions between its customers through electronic book-changes in accounts of its customers, thereby eliminating the need for physical movement of certificates. Clearstream provides to its customers, among other things, services for safekeeping, administration, clearance and settlement of internationally traded securities and securities lending and borrowing. Clearstream interfaces with domestic markets in several countries. As a professional depositary, Clearstream is subject to regulation by the Luxembourg Commission for the Supervision of the Financial Section. Clearstream customers are recognized financial institutions around the world, including underwriters, securities brokers and dealers, banks, trust companies, clearing corporations and other organizations and may include the underwriters. Indirect access to Clearstream is also available to others, such as banks, brokers, dealers and trust companies that clear through or maintain a custodial relationship with a Clearstream customer either directly or indirectly.

We understand that Euroclear was created in 1968 to hold securities for participants of Euroclear and to clear and settle transactions between Euroclear participants through simultaneous electronic book-entry delivery against payment, thereby eliminating the need for physical movement of certificates and any risk from lack of simultaneous transfers of securities and cash. Euroclear provides various other services, including securities lending and borrowing and interfaces with domestic markets in several countries. Euroclear is operated by Euroclear Bank S.A./N.V., which we refer to as the Euroclear Operator, under contract with Euroclear Clearance Systems S.C., a Belgian cooperative corporation, which we refer to as the Cooperative. All operations are conducted by the Euroclear Operator, and all Euroclear securities clearance accounts and Euroclear cash accounts are accounts with the Euroclear Operator, not the Cooperative. The Cooperative establishes policy for Euroclear on behalf of Euroclear participants. Euroclear participants include banks (including central banks), securities brokers and dealers, and other professional financial intermediaries and may include the underwriters. Indirect access to Euroclear is also available to other firms that clear through or maintain a custodial relationship with a Euroclear participant, either directly or indirectly.

We understand that the Euroclear Operator is licensed by the Belgian Banking and Finance Commission to carry out banking activities on a global basis. As a Belgian bank, it is regulated and examined by the Belgian Banking and Finance Commission.

We have provided the descriptions of the operations and procedures of DTC, Clearstream and Euroclear in this prospectus supplement solely as a matter of convenience, and we make no representation or warranty of any kind with respect to these operations and procedures. These operations and procedures are solely within the control of those organizations and are subject to change by them from time to time. None of the Issuer, the underwriters or the Trustee takes any responsibility for these operations or procedures, and you are urged to contact DTC, Clearstream and Euroclear or their participants directly to discuss these matters.

The laws of some jurisdictions may require that purchasers of securities take physical delivery of those securities in definitive form. Accordingly, the ability to transfer interests in the Notes represented by a global note to those persons may be limited. In addition, because DTC can act only on behalf of its participants, who in turn act on behalf of persons who hold interests through participants, the ability of a person having an interest in Notes represented by a global note to pledge or transfer those interests to persons or entities that do not participate in DTC's system, or otherwise to take actions in respect of such interest, may be affected by the lack of a physical definitive security in respect of such interest.

So long as DTC or its nominee is the registered owner of a global note, DTC or that nominee will be considered the sole owner or holder of the Notes represented by that global note for all purposes under the Indenture and under the Notes. Except as provided below, owners of beneficial interests in a global note will not be entitled to have Notes represented by that global note registered in their names, will not receive or be entitled to receive physical delivery of certificated Notes and will not be considered the owners or holders thereof under the Indenture or under the Notes for any purpose, including with respect to the giving of any direction, instruction or approval to the Trustee. Accordingly, each holder owning a beneficial interest in a global note must rely on the procedures of DTC and, if that holder is not a direct or indirect participant, on the procedures of the participant through which that holder owns its interest, to exercise any rights of a holder of Notes under the Indenture or a global note.

Neither the Issuer nor the Trustee will have any responsibility or liability for any aspect of the records relating to or payments made on account of Notes by DTC, Clearstream or Euroclear, or for maintaining, supervising or reviewing any records of those organizations relating to the Notes.

Payments on the Notes represented by the global notes will be made to DTC or its nominee, as the case may be, as the registered owner thereof. We expect that DTC or its nominee, upon receipt of any payment on the Notes represented by a global note, will credit participants' accounts with payments in amounts proportionate to their respective beneficial interests in the global note as shown in the records of DTC or its nominee. We also expect that payments by participants to owners of beneficial interests in the global note held through such participants will be governed by standing instructions and customary practice as is now the case with securities held for the accounts of customers registered in the names of nominees for such customers. The participants will be solely responsible for those payments.

Distributions on the Notes held beneficially through Clearstream will be credited to cash accounts of its customers in accordance with its rules and procedures, to the extent received by the U.S. depositary for Clearstream.

Securities clearance accounts and cash accounts with the Euroclear Operator are governed by the Terms and Conditions Governing Use of Euroclear and the related Operating Procedures of the Euroclear System, and applicable Belgian law (collectively referred to herein as the Terms and Conditions). The Terms and Conditions govern transfers of securities and cash within Euroclear, withdrawals of securities and cash from Euroclear, and receipts of payments with respect to securities in Euroclear. All securities in Euroclear are held on a fungible basis without attribution of specific certificates to specific securities clearance accounts. The Euroclear Operator acts under the Terms and Conditions only on behalf of Euroclear participants and has no record of or relationship with persons holding through Euroclear participants.

Distributions on the Notes held beneficially through Euroclear will be credited to the cash accounts of its participants in accordance with the Terms and Conditions, to the extent received by the U.S. depositary for Euroclear.

Initial settlement for the Notes will be made in immediately available funds. Secondary market trading between DTC participants will occur in the ordinary way in accordance with DTC rules and will be settled in immediately available funds. Secondary market trading between Clearstream customers and/or Euroclear participants will occur in the ordinary way in accordance with the applicable rules and operating procedures of Clearstream and Euroclear, as applicable, and will be settled using the procedures applicable to conventional Eurobonds in immediately available funds.

Cross-market transfers between persons holding directly or indirectly through DTC, on the one hand, and directly or indirectly through Clearstream customers or Euroclear participants, on the other, will be effected through DTC in accordance with DTC rules on behalf of the relevant European international clearing system by the U.S. depositary. Such cross-market transactions, however, will require delivery of instructions to the relevant European international clearing system by the counterparty in such system in accordance with its rules and procedures and within its established deadlines (European time). The relevant European international clearing system will, if the transaction meets its settlement requirements, deliver instructions to the U.S. depositary to take action to effect final settlement on its behalf by delivering or receiving the Notes in DTC, and making or receiving payment in accordance with normal procedures for same-day funds settlement applicable to DTC. Clearstream customers and Euroclear participants may not deliver instructions directly to their U.S. depositaries.

Because of time-zone differences, credits of the Notes received in Clearstream or Euroclear as a result of a transaction with a DTC participant will be made during subsequent securities settlement processing and dated the business day following the DTC settlement date. Such credits or any transactions in the Notes settled during such processing will be reported to the relevant Clearstream customers or Euroclear participants on such business day. Cash received in Clearstream or Euroclear as a result of sales of the Notes by or through a Clearstream customer or a Euroclear participant to a DTC participant will be received with value on the DTC settlement date but will be available in the relevant Clearstream or Euroclear cash account only as of the business day following settlement in DTC.

Although DTC, Clearstream and Euroclear have agreed to the foregoing procedures to facilitate transfers of the Notes among participants of DTC, Clearstream and Euroclear, they are under no obligation to perform or continue to perform such procedures and such procedures may be changed or discontinued at any time.

The Issuer will issue certificated Notes to each person that DTC identifies as the beneficial owner of the Notes represented by a global note upon surrender by DTC of the global note if:

Neither the Issuer nor the Trustee will be liable for any delay by DTC, its nominee or any direct or indirect participant in identifying the beneficial owners of the Notes. We and the Trustee may conclusively rely on, and will be protected in relying on, instructions from DTC or its nominee for all purposes, including with respect to the registration and delivery, and the respective principal amounts, of the certificated Notes to be issued.

At the present time, there is no Bermuda income or profits tax, withholding tax, capital gains tax, capital transfer tax, estate duty or inheritance tax payable by us or by our shareholders in respect of our shares. We have obtained an assurance from the Minister of Finance of Bermuda under the Exempted Undertakings Tax Protection Act 1966 of Bermuda, as amended, that, in the event that any legislation is enacted in Bermuda imposing any tax computed on profits or income, or computed on any capital asset, gain or appreciation or any tax in the nature of estate duty or inheritance tax, such tax shall not, until March 31, 2035, be applicable to us or to any of our operations or to our shares, debentures or other obligations except insofar as such tax applies to persons ordinarily resident in Bermuda or is payable by us in respect of real property owned or leased by us in Bermuda. Given the limited duration of the Bermuda Minister of Finance's assurance, we cannot assure you that we will not be subject to any Bermuda tax after March 31, 2035.

The following discussion of U.S. Federal income tax matters is based on the Code, judicial decisions, administrative pronouncements, and existing and proposed regulations issued by the U.S. Department of the Treasury, all of which are subject to change, possibly with retroactive effect. This discussion does not address any U.S. state or local taxes. You are encouraged to consult your own tax advisor regarding the particular U.S. Federal, state and local and foreign income and other tax consequences of acquiring, owning and disposing of the Additional Notes that may be applicable to you.

We have elected to treat a majority of our subsidiaries as disregarded entities for U.S. Federal income tax purposes. The entities that are considered disregarded entities for U.S. Federal income tax purposes should be treated as branches rather than corporations for U.S. Federal income tax purposes. Currently, no election has been filed to treat GasLog LNG Services Ltd., GasLog Services UK Ltd., GasLog Asia Pte. Ltd., GasLog Investments Ltd., GasLog Monaco S.A.M., GasLog Shipping Limited, GasLog Shipping Company Ltd., and Egypt LNG Shipping Ltd. as disregarded entities for U.S. Federal income tax purposes. As a result, these entities and GasLog Services U.S. Inc. will continue to be treated as corporations for U.S. Federal income tax purposes.

Subject to the discussion of "effectively connected" income below, unless we are exempt from U.S. Federal income tax under the rules contained in Section 883 of the Code, we will be subject to U.S. Federal income tax under the rules of Section 887 of the Code, which imposes on us a 4% U.S. Federal income tax in respect of our U.S. source gross transportation income (without the allowance for deductions).

For this purpose, U.S. source gross transportation income includes 50% of the shipping income that is attributable to transportation that begins or ends (but that does not both begin and end) in the United States. Shipping income attributable to transportation exclusively between non-U.S. ports is generally not subject to any U.S. Federal income tax.

Under Section 883 of the Code and the regulations thereunder, we will be exempt from U.S. Federal income tax on our U.S. source gross transportation income if:

We have qualified for the statutory tax exemption for the year of 2018 and intend to continue to qualify for the foreseeable future. However, no assurance can be given that this will be the case. If we are not entitled to this exemption under Section 883 for any taxable year we would be subject to the 4% U.S. Federal income tax (subject to the discussion of "effectively connected income" below).

To the extent the exemption under Section 883 is unavailable, our U.S. source gross transportation income in future years that is considered to be "effectively connected" with the conduct of a U.S. trade or business is subject to the U.S. corporate income tax currently imposed at rate of up to 21% (net of applicable deductions). In addition, we may be subject to the 30% U.S. "branch profits" tax on earnings effectively connected with the conduct of such trade or business, as determined after allowance for certain adjustments, and on certain interest paid or deemed paid attributable to the conduct of our U.S. trade or business.

Our U.S. source gross transportation income would be considered effectively connected with the conduct of a U.S. trade or business only if:

We believe that we will not meet these conditions because we will not have, or permit circumstances that would result in having, such a fixed place of business in the United States or any ship sailing to or from the United States on a regularly scheduled basis.

In addition, income attributable to transportation that both begins and ends in the United States is not subject to the tax rules described above. Such income is subject to either a 30% gross-basis tax or to U.S. corporate income tax on net income at a rate of up to 21% (and the branch profits tax discussed above). Although there can be no assurance, we do not expect to engage in transportation that produces shipping income of this type.

Regardless of whether we qualify for the exemption under Section 883 of the Code, we will not be subject to U.S. Federal income taxation with respect to gain realized on a sale of a ship, provided the sale is considered to occur outside of the United States (as determined under U.S. tax principles). In general, a sale of a ship will be considered to occur outside of the United States for this purpose if title to the ship (and risk of loss with respect to the ship) passes to the buyer outside of the United States. We expect that any sale of a ship will be so structured that it will be considered to occur outside of the United States.

You are a "U.S. holder" if you are a beneficial owner of the Additional Notes and you are (i) a U.S. citizen or resident, (ii) a U.S. corporation (or other U.S. entity taxable as a corporation), (iii) an estate the income of which is subject to U.S. Federal income taxation regardless of its source or (iv) a trust if (x) a court within the United States is able to exercise primary jurisdiction over the administration of the trust and one or more U.S. persons have the authority to control all substantial decisions of the trust or (y) the trust has a valid election in effect to be treated as a U.S. person for U.S. Federal income tax purposes.

If a partnership holds the Additional Notes, the tax treatment of a partner will generally depend upon the status of the partner and upon the activities of the partnership. If you are a partner in a partnership holding the Additional Notes, you should consult your own tax advisor.

We intend to treat the issuance of the Additional Notes as a "qualified reopening" of the Existing Notes. For U.S. Federal income tax purposes, debt instruments issued in a qualified reopening are deemed to be part of the same issue as the original debt instruments. Under the treatment described in this paragraph, all of the Additional Notes issued pursuant to this prospectus supplement will be deemed to have the same issue date and the same issue price as the Existing Notes for U.S. Federal income tax purposes. The remainder of this discussion assumes that the issuance of the Additional Notes offered hereby will be treated as a qualified reopening of the Existing Notes.

A portion of the price paid for the Additional Notes may be attributable to the amount of interest accrued prior to the date such Additional Notes are purchased ("pre-issuance accrued interest"). In such circumstances, we intend to take the position that, on the first interest payment date, a portion of the interest received in an amount equal to the pre-issuance accrued interest will be treated as a nontaxable return of the pre-issuance accrued interest rather than a payment of interest on the Additional Notes. A U.S. holder's tax basis in the Additional Note will not include the portion of the purchase price attributable to the pre-issuance accrued interest.

If a U.S. holder purchases an Additional Note for a price (excluding any amount attributable to pre-issuance accrued interest as described above) in excess of the stated principal amount of such Additional Note, such U.S. holder will be considered to have acquired an Additional Note with bond premium in an amount equal to such excess. Generally, a U.S. holder may elect to amortize bond premium under the constant yield method over the remaining term of the Additional Note. However, because the Additional Notes may be redeemed by us prior to maturity at a premium, special rules apply that may reduce, eliminate or defer the amount of premium that a U.S. holder may amortize with respect to the Additional Notes. If a U.S. holder elects to amortize bond premium, the election

will apply to all taxable debt instruments having bond premium that such U.S. holder owns or subsequently acquires on or after the first day of the first taxable year to which the election applies, and the election may not be revoked without the consent of the IRS. Amortizable bond premium will be treated as an offset to interest income of an Additional Note rather than as a separate item of deduction. If a U.S. holder does not elect to amortize bond premium, then that premium will decrease the gain or increase the loss such U.S. holder would otherwise recognize on the disposition of such Additional Note. The rules regarding instruments purchased with amortizable bond premium are complex and, accordingly, you should consult your own tax advisors concerning the application of such rules to the Additional Notes.

Interest (other than pre-issuance accrued interest) on the Additional Notes generally will be taxable to a U.S. holder as ordinary income at the time such interest is received or accrued, in accordance with such U.S. holder's method of tax accounting for U.S. Federal income tax purposes. Interest (other than pre-issuance accrued interest) received or accrued on the Additional Notes generally will be foreign source income and, depending on your circumstances, treated as either "passive" or "general" category income for purposes of computing allowable foreign tax credits for U.S. Federal income tax purposes.

A U.S. holder generally will recognize capital gain or loss upon a sale, exchange or other disposition of the Additional Notes in an amount equal to the difference between the amount realized by the U.S. holder from such sale, exchange or other disposition (including any make-whole amount received upon redemption, but less any amounts attributable to accrued but unpaid interest, which, unless it represents pre-issuance accrued interest, will be taxable as ordinary interest income to the extent not previously included in income) and the U.S. holder's adjusted tax basis in such Additional Notes. A U.S. holder's adjusted tax basis in an Additional Note will generally equal the acquisition cost of such Additional Note (excluding the portion of the purchase price attributable to pre-issuance accrued interest) decreased by amortizable bond premium that such U.S. holder previously elected to amortize against interest income. Such gain or loss will generally be treated as capital gain or loss, and generally will be long-term capital gain or loss if the U.S. holder's holding period is greater than one year at the time of the sale, exchange or other disposition. Such capital gain or loss will generally be treated as U.S. source income or loss, as applicable, for U.S. foreign tax credit purposes. Long-term capital gains of non-corporate U.S. holders are generally eligible for a reduced tax rate. A U.S. holder's ability to deduct capital losses against income is subject to certain limitations.

Each U.S. holder who is an individual, estate or trust is generally subject to a 3.8% Medicare tax on the lesser of (i) such U.S. holder's "net investment income" for the relevant tax year, and (ii) the excess of such U.S. holder's modified adjusted gross income for the tax year over a certain threshold (which in the case of individuals will be between $125,000 and $250,000, depending on the individual's circumstances). For this purpose, net investment income generally includes interest income and capital gains from the sale, exchange or other disposition of the Additional Notes, subject to certain exceptions. You are encouraged to consult your own tax advisor regarding the applicability of the Medicare tax to your income and gains from your ownership or disposition of the Additional Notes.

You are a "non-U.S. holder" if you are a beneficial owner of the Notes (other than a partnership for U.S. tax purposes) and you are not a U.S. holder.

Non-U.S. holders generally will not be subject to U.S. Federal income tax or withholding tax on interest received from us with respect to the Additional Notes, unless that interest is effectively connected with the non-U.S. holder's conduct of a trade or business in the United States. If the non-U.S. holder is entitled to the benefits of an applicable U.S. income tax treaty with respect to such interest, that income is taxable only if it is attributable to a permanent establishment maintained by the non-U.S. holder in the United States.

You generally will not be subject to U.S. Federal income tax or withholding tax on any gain realized upon the sale, exchange or other disposition of the Additional Notes, unless:

Gain that is effectively connected with the conduct of a trade or business in the United States (or so treated) generally will be subject to U.S. Federal income tax (net of certain deductions) at regular U.S. Federal income tax rates. If you are a corporate non-U.S. holder, your earnings and profits that are attributable to the effectively connected income (subject to certain adjustments) may be subject to an additional U.S. branch profits tax at a rate of 30% (or such lower rate as may be specified by an applicable tax treaty).

In general, if you are a non-corporate U.S. holder, interest payments made within the United States will be subject to information reporting requirements and backup withholding tax if you:

If you are a non-U.S. holder, you may be required to establish your exemption from information reporting and backup withholding by certifying your status on IRS Form W-8BEN, W-8BEN-E, W-8ECI or W-8IMY, as applicable.

If you sell the Additional Notes to or through a U.S. office or broker, the payment of the sales proceeds is subject to both U.S. backup withholding and information reporting unless you certify that you are a non-U.S. person, under penalties of perjury, or you otherwise establish an exemption. If you sell the Additional Notes through a non-U.S. office of a non-U.S. broker and the sales proceeds are paid to you outside the United States, then information reporting and backup withholding generally will not apply to that payment.

However, U.S. information reporting requirements (but not backup withholding) will apply to a payment of sales proceeds, even if that payment is made outside the United States, if you sell the

Additional Notes through a non-U.S. office of a broker that is a U.S. person or has certain other connections with the United States.

Backup withholding tax is not an additional tax. Rather, you generally may obtain a refund of any amounts withheld under backup withholding rules that exceed your income tax liability by accurately completing and timely filing a refund claim with the IRS.

U.S. individuals who hold certain "specified foreign financial assets" with values in excess of certain dollar thresholds are subject to U.S. return disclosure obligations (and related penalties for failure to disclose). Such U.S. individuals are required to file IRS Form 8938 with their U.S. Federal income tax returns. Notes of a foreign corporation, including the Additional Notes, are a specified foreign asset for this purpose. You are encouraged to consult with your own tax advisors regarding the filing of IRS Form 8938.

We estimate the expenses in connection with the issuance and distribution of the Additional Notes in this offering, other than the underwriting discount, will be as follows:

Credit Suisse Securities (USA) LLC, DNB Markets, Inc. and Stifel, Nicolaus & Company, Incorporated are acting as joint book-running managers of this offering. Subject to the terms and conditions stated in the underwriting agreement dated the date of this prospectus, each underwriter named below has severally agreed to purchase, and we have agreed to sell to that underwriter, the principal amount of Additional Notes set forth opposite the underwriter's name.

The underwriting agreement provides that the obligations of the underwriters to purchase the Additional Notes in this offering are subject to approval of legal matters by counsel and to other conditions. The underwriters are obligated to purchase all the Additional Notes if they purchase any of the Additional Notes.

Additional Notes sold by the underwriters to the public will initially be offered at the initial public offering price set forth on the cover of this prospectus. Any Additional Notes sold by the underwriters to securities dealers may be sold at a discount from the initial public offering price not to exceed $ per note in the case of sales to retail investors, and $ per note in the case of sales to institutional investors. If all the Additional Notes are not sold at the initial offering price, the underwriters may change the offering price and the other selling terms.

The following table shows the underwriting discounts and commissions that we are to pay to the underwriters in connection with this offering.

We estimate that our total expenses for this offering will be approximately $430,000.

In connection with the offering, the underwriters may purchase and sell the Notes in the open market. Purchases and sales in the open market may include short sales, purchases to cover short positions and stabilizing purchases.

Purchases to cover short positions and stabilizing purchases, as well as other purchases by the underwriters for their own accounts, may have the effect of preventing or retarding a decline in the market price of the Notes. They may also cause the price of the Notes to be higher than the price that would otherwise exist in the open market in the absence of these transactions. The underwriters may conduct these transactions in the over-the-counter market or otherwise. If the underwriters commence any of these transactions, they may discontinue them at any time.

We have agreed to indemnify the underwriters against certain liabilities, including liabilities under the Securities Act, or to contribute to payments the underwriters may be required to make because of any of those liabilities.

The underwriters are full service financial institutions engaged in various activities, which may include securities trading, commercial and investment banking, financial advisory, investment management, principal investment, hedging, financing and brokerage activities. The underwriters and their respective affiliates have in the past performed commercial banking, investment banking and advisory services for us and to persons and entities with relationships to us from time to time for which they have received customary fees and reimbursement of expenses and may, from time to time, engage in transactions with and perform services for us and to persons and entities with relationships to us in the ordinary course of their business for which they may receive customary fees and reimbursement of expenses. In the ordinary course of their various business activities, the underwriters and their respective affiliates may make or hold a broad array of investments and actively trade debt and equity securities (or related derivative securities) and financial instruments (which may include bank loans and/or credit default swaps) for their own account and for the accounts of their customers and may at any time hold long and short positions in such securities and instruments. Such investments and securities activities may involve securities and/or instruments of ours or our affiliates. The underwriters and their affiliates may also make investment recommendations and/or publish or express independent research views in respect of such securities or financial instruments and may hold, or recommend to clients that they acquire, long and/or short positions in such securities and instruments.

The Notes may be sold only to purchasers purchasing, or deemed to be purchasing, as principal that are accredited investors, as defined in National Instrument 45-106—Prospectus Exemptions or subsection 73.3(1) of the Securities Act (Ontario), and that are permitted clients, as defined in National Instrument 31-103—Registration Requirements, Exemptions and Ongoing Registrant Obligations. Any resale of the Notes must be made in accordance with an exemption from, or in a transaction not subject to, the prospectus requirements of applicable securities laws.

Securities legislation in certain provinces or territories of Canada may provide a purchaser with remedies for rescission or damages if this prospectus supplement (including any amendment thereto) contains a misrepresentation, provided that the remedies for rescission or damages are exercised by the purchaser within the time limit prescribed by the securities legislation of the purchaser's province or territory. The purchaser should refer to any applicable provisions of the securities legislation of the purchaser's province or territory for particulars of these rights or consult with a legal advisor.

Pursuant to section 3A.3 of National Instrument 33-105—Underwriting Conflicts ("NI 33-105"), the underwriters are not required to comply with the disclosure requirements of NI 33-105 regarding underwriter conflicts of interest in connection with this prospectus supplement.

The Notes are not intended to be offered, sold or otherwise made available to and should not be offered, sold or otherwise made available to any retail investor in the European Economic Area ("EEA"). For these purposes, a retail investor means a person who is one (or more) of: (i) a retail client as defined in point (11) of Article 4(1) of Directive 2014/65/EU (as amended, "MiFID II"); or (ii) a customer within the meaning of Directive 2016/97/EU (as amended, the "Insurance Distribution Directive"), where that customer would not qualify as a professional client as defined in point (10) of Article 4(1) of MiFID II; or (iii) not a qualified investor as defined in Directive 2003/71/EC (as amended, the "Prospectus Directive"). Consequently, no key information document required by Regulation (EU) No 1286/2014 (as amended, the "PRIIPs Regulation") for offering or selling the Notes or otherwise making them available to retail investors in the EEA has been prepared and therefore offering or selling the Notes or otherwise making them available to any retail investor in the EEA may be unlawful under the PRIIPS Regulation. This prospectus supplement has been prepared on the basis that any offer of Notes in any Member State of the EEA will be made pursuant to an exemption under the Prospectus Directive from the requirement to publish a prospectus for offers of Notes. This prospectus supplement and the accompanying prospectus is not a prospectus for the purposes of the Prospectus Directive.

This prospectus supplement is only being distributed to, and is only directed at, persons in the United Kingdom that are qualified investors within the meaning of Article 2(l)(e) of the Prospectus Directive that are also (i) investment professionals falling within Article 19(5) of the Financial Services and Markets Act 2000 (Financial Promotion) Order 2005 (the "Order"), or (ii) high net worth entitles, and other persons to whom it may lawfully be communicated, falling within Article 49(2)(a) to (d) of the Order (each such person being referred to as a "relevant person"). This prospectus supplement and its contents are confidential and should not be distributed, published or reproduced (in whole or in part) or disclosed by recipients to any other persons in the United Kingdom. Any person in the United Kingdom that is not a relevant person should not act or reply on this document or any of its contents.

This prospectus supplement and the accompanying prospectus have not been registered as a prospectus with the Monetary Authority of Singapore (the "MAS"). Accordingly, this prospectus supplement and the accompanying prospectus and any other document or material in connection with the offer or sale, or invitation for subscription or purchase, of the Notes may not be circulated or distributed, nor may the Notes be offered or sold, or be made the subject of an invitation for subscription or purchase, whether directly or indirectly, to persons in Singapore other than: (i) to an institutional investor under Section 274 of the Securities and Futures Act, Chapter 289 of Singapore (the "SFA"), (ii) to a relevant person (as defined in Section 275(2) of the SFA), or any person pursuant to Section 275(1A), and in accordance with the conditions, specified in Section 275 of the SFA or (iii) otherwise pursuant to, and in accordance with the conditions of, any other applicable provision of the SFA.

Where the Notes are subscribed or purchased under Section 275 by a relevant person which is: (i) a corporation (which is not an accredited investor) the sole business of which is to hold investments

and the entire share capital of which is owned by one or more individuals, each of whom is an accredited investor or (ii) a trust (where the trustee is not an accredited investor) whose sole purpose is to hold investments and each beneficiary is an accredited investor, shares, debentures and units of shares and debentures of that corporation or the beneficiaries' rights and interest in that trust shall not be transferable for 6 months after that corporation or that trust has acquired the Notes under Section 275 except: (a) to an institutional investor under Section 274 of the SFA or to a relevant person, or any person pursuant to Section 275(1A), and in accordance with the conditions, specified in Section 275 of the SFA, (b) where no consideration is given for the transfer or (c) by operation of law.

Solely for the purposes of our obligations pursuant to Sections 309B(1)(a) and 309B(1)(c) of the SFA, we have determined, and hereby notify all relevant persons (as defined in Section 309A of the SFA) that the Notes are "prescribed capital markets products" (as defined in the Securities and Futures (Capital Markets Products) Regulations 2018) and Excluded Investment Products (as defined in MAS Notice SFA 04-N12: Notice on the Sale of Investment Products and MAS Notice FAA-N16: Notice on Recommendations on Investment Products).

The Notes may not be publicly offered in Switzerland and will not be listed on the SIX Swiss Exchange (the "SIX") or on any other stock exchange or regulated trading facility in Switzerland. This document has been prepared without regard to the disclosure standards for issuance prospectuses under art. 652a or art. 1156 of the Swiss Code of Obligations or the disclosure standards for listing prospectuses under art. 27 ff. of the SIX Listing Rules or the listing rules of any other stock exchange or regulated trading facility in Switzerland. Neither this document nor any other offering or marketing material relating to the Notes or the offering may be publicly distributed or otherwise made publicly available in Switzerland.

Neither this prospectus supplement nor any other offering or marketing material relating to the offering, the issuer, or the Notes have been or will be filed with or approved by any Swiss regulatory authority. In particular, this prospectus supplement will not be filed with, and the offer of Notes will not be supervised by, the Swiss Financial Market Supervisory Authority, and the offer of Notes has not been and will not be authorized under the Swiss Federal Act on Collective Investment Schemes (the "CISA"). The investor protection afforded to acquirers of interests in collective investment schemes under the CISA does not extend to acquirers of Notes.

We are a Bermuda exempted company. Our registered address in Bermuda is Clarendon House, 2 Church Street, Hamilton, HM 11, Bermuda. A majority of our directors and some of the named experts referred to in this prospectus supplement are not residents of the United States, and a substantial portion of our assets are located outside the United States. As a result, it may be difficult for investors to effect service of process on those persons in the United States or to enforce in the United States judgments obtained in U.S. courts against us or those persons based on the civil liability provisions of the U.S. securities laws. It is doubtful whether courts in Bermuda will enforce judgments obtained in other jurisdictions, including the United States, against us or our directors or officers under the securities laws of those jurisdictions or entertain actions in Bermuda against us or our directors or officers under the securities laws of other jurisdictions.

Certain legal matters, including tax matters, with respect to the laws of Bermuda will be passed upon for us by our special counsel as to Bermuda law, Conyers Dill & Pearman Limited. The validity of the Notes and certain matters with respect to this offering, including tax matters with respect to U.S. law, will be passed upon for us by Cravath, Swaine & Moore LLP, New York, New York. Cravath, Swaine & Moore LLP may rely on the opinion of Conyers Dill & Pearman Limited for all matters of Bermuda law. Certain matters with respect to this offering will be passed upon for the underwriters by Morgan, Lewis & Bockius LLP, New York, New York.

The consolidated financial statements as of December 31, 2017 and 2018, and for each of the three years in the period ended December 31, 2018, incorporated in this prospectus supplement by reference from the Company's Annual Report on Form 20-F for the year ended December 31, 2018, and the effectiveness of GasLog Ltd.'s internal control over financial reporting as of December 31, 2018 have been audited by Deloitte LLP, an independent registered public accounting firm, as stated in their reports, which are incorporated herein by reference. Such financial statements have been so incorporated in reliance upon the reports of such firm given upon their authority as experts in accounting and auditing.

The offices of Deloitte LLP are located at 1 New Street Square, London, EC4A 3HQ, United Kingdom.

We have filed with the SEC a registration statement on Form F-3 under the Securities Act with respect to the offer and sale of securities pursuant to this prospectus supplement. For purposes of this section, the term "registration statement" means the original registration statement and any and all amendments, including the schedules and exhibits to the original registration statement and any amendments. This prospectus supplement, filed as a part of the registration statement, does not contain all of the information set forth in the registration statement or the exhibits and schedules thereto in accordance with the rules and regulations of the SEC and no reference is hereby made to such omitted information. Statements made in this prospectus supplement concerning the contents of any contract, agreement or other document filed as an exhibit to the registration statement are summaries of all of the material terms of such contracts, agreements or documents, but do not repeat all of their terms. Reference is made to each such exhibit for a more complete description of the matters involved and such statements shall be deemed qualified in their entirety by such reference. The SEC maintains a website at http://www.sec.gov that contains reports, proxy and information statements and other information regarding registrants that file electronically with the SEC. For further information pertaining to the securities offered by this prospectus supplement and GasLog Ltd., reference is made to the registration statement.

We are subject to the information and periodic reporting requirements of the Exchange Act of 1934, as amended (the "Exchange Act"), and we file periodic reports and other information with the SEC. These periodic reports and other information are available for inspection and copying at the SEC's public reference facilities and the website of the SEC referred to above. As a "foreign private issuer", we are exempt from the rules under the Exchange Act prescribing the furnishing and content of proxy statements to shareholders, but we are required to furnish certain proxy statements to shareholders under NYSE rules. Those proxy statements are not expected to conform to Schedule 14A of the proxy rules promulgated under the Exchange Act. In addition, as a "foreign private issuer", we are exempt from the rules under the Exchange Act relating to short swing profit reporting and liability.

The SEC allows us to "incorporate by reference" information that we file with the SEC. This means that we can disclose important information to you by referring you to those filed documents. The information incorporated by reference is considered to be a part of this prospectus supplement, and information that we file later with the SEC will also be considered to be part of this prospectus supplement and will automatically update and supersede previously filed information, including information contained in this prospectus supplement.

We are also incorporating by reference all subsequent annual reports on Form 20-F that we file with the SEC and certain reports on Form 6-K that we furnish to the SEC after the date of this prospectus supplement (if they state that they are incorporated by reference into this prospectus supplement) until we file a post-effective amendment indicating that the offering of the Notes made by this prospectus supplement has been terminated. In all cases, you should rely on the later information over different information included in this prospectus supplement.

We will provide, free of charge upon written or oral request, to each person to whom this prospectus supplement is delivered, a copy of any or all of the information that has been incorporated by reference into this prospectus supplement, but which has not been delivered with the prospectus supplement. Copies of these documents also may be obtained on the "Investor Relations" section of our website at www.gaslogltd.com. Requests for such information should be made to us at the following address:

GasLog Ltd.
Gildo Pastor Center
7 Rue du Gabian
MC 98000, Monaco
+ 377 97 97 51 15
Attention: Nicola Lloyd, General Counsel

You should assume that the information appearing in this prospectus supplement and any accompanying prospectus supplement, as well as the information we previously filed with the SEC and incorporated by reference, is accurate as of the dates on the front cover of those documents only. Our business, financial condition and results of operations and prospects may have changed since those dates.

Common Shares
Preference Shares
8.75% Series A Preference Shares
Debt Securities
Warrants
Rights
Units

Through this prospectus, we may offer common shares, preference shares, Series A Preference Shares, debt securities, warrants, rights and units from time to time. We may also offer securities of the types listed above that are convertible or exchangeable into one or more of the securities listed above. When we decide to sell a particular class or series of securities, we will provide specific terms of the offered securities in a prospectus supplement.

The securities covered by this prospectus may be offered and sold from time to time in one or more offerings, which may be through one or more underwriters, dealers and agents, or directly to the purchasers. The names of any underwriters, dealers or agents, if any, will be included in a supplement to this prospectus.

This prospectus describes some of the general terms that may apply to these securities and the general manner in which they may be offered. The specific terms of any securities to be offered, and the specific manner in which they may be offered, will be described in one or more supplements to this prospectus. A prospectus supplement may also add, update or change information contained in this prospectus.

Our common shares are traded on the New York Stock Exchange under the symbol "GLOG".

Our 8.75% Series A Preference Shares are traded on the New York Stock Exchange under the symbol "GLOG PR A".

Our principal executive offices are located at Gildo Pastor Center, 7 Rue du Gabian, MC 98000, Monaco. Our telephone number at such address is +377 97 97 51 15.

Investing in our securities involves risks. Before buying any securities you should carefully read the section entitled "Risk Factors" on page 5 of this prospectus.

Neither the Securities and Exchange Commission nor any state or other securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

Consent under the Exchange Control Act 1972 (and its related regulations) has been obtained from the Bermuda Monetary Authority for the issue and transfer of our offered securities to and between residents and non-residents of Bermuda for exchange control purposes provided our shares remain listed on an appointed stock exchange, which includes the New York Stock Exchange. In granting such consent, the Bermuda Monetary Authority accepts no responsibility for our financial soundness or the correctness of any of the statements made or opinions expressed in this prospectus.

All statements in this prospectus that are not statements of historical fact are "forward-looking statements" within the meaning of the United States Private Securities Litigation Reform Act of 1995. Forward-looking statements include statements that address activities, events or developments that the Company expects, projects, believes or anticipates will or may occur in the future, particularly in relation to our operations, cash flows, financial position, liquidity and cash available for dividends or distributions, plans, strategies, business prospects and changes and trends in our business and the markets in which we operate. In some cases, predictive, future-tense or forward-looking words such as "believe", "intend", "anticipate", "estimate", "project", "forecast", "plan", "potential", "may", "should", "could" and "expect" and similar expressions are intended to identify forward-looking statements, but are not the exclusive means of identifying such statements. In addition, we and our representatives may from time to time make other oral or written statements which are forward-looking statements, including in our periodic reports that we file with the Securities and Exchange Commission (the "SEC"), other information sent to our security holders and other written materials. We caution that these forward-looking statements represent our estimates and assumptions only as of the date of this prospectus or the date on which such oral or written statements are made, as applicable, about factors that are beyond our ability to control or predict, and are not intended to give any assurance as to future results. Any of these factors or a combination of these factors could materially affect future results of operations and the ultimate accuracy of the forward-looking statements. Accordingly, you should not unduly rely on any forward-looking statements.

Factors that might cause future results and outcomes to differ include, but are not limited to, the following:

We caution that these and other forward-looking statements included in this prospectus represent our estimates and assumptions only as of the date of this prospectus and are not intended to give any assurance as to future results. Many of the forward-looking statements included in this prospectus are based on our assumptions about factors that are beyond our ability to control or predict. Assumptions, expectations, projections, intentions and beliefs about future events may, and often do, vary from actual results and these differences can be material. The reasons for this include the risks, uncertainties and factors described in the "Risk Factors" section of this prospectus. As a result, the forward-looking events discussed in this prospectus might not occur and our actual results may differ materially from those anticipated in the forward-looking statements. Accordingly, you should not unduly rely on any forward-looking statements.

We undertake no obligation to update or revise any forward-looking statements contained in this prospectus, whether as a result of new information, future events, a change in our views or expectations or otherwise, except as required by applicable law. New factors emerge from time to time, and it is not possible for us to predict all of these factors. Further, we cannot assess the impact of each such factor on our business or the extent to which any factor, or combination of factors, may cause actual results to be materially different from those contained in any forward-looking statement.

Unless otherwise indicated, references in this prospectus to "GasLog", the "Company", the "Group", "we", "our", "us" or similar terms refer to GasLog Ltd. or any one or more of its subsidiaries (including GasLog Partners LP) or their predecessors, or to such entities collectively, except that when such terms are used in this prospectus in reference to the common shares or the 8.75% Series A Cumulative Redeemable Perpetual Preference Shares (the "Series A Preference Shares"), they refer to GasLog Ltd.; "GasLog Partners" or the "Partnership", refers to GasLog Partners LP, a master limited partnership formed by GasLog to own, operate and acquire LNG carriers under multi-year charters, or any one or more of GasLog Partners' subsidiaries; "GasLog LNG Services" refers to GasLog LNG Services Ltd., our wholly owned subsidiary; "our vessels" or "our ships" refers to the LNG carriers owned or controlled by the Company and its subsidiaries, including the LNG carriers owned by GasLog Partners; "our wholly owned vessels" or "our wholly owned ships" refers to the LNG carriers owned by the Company and its subsidiaries, excluding any LNG carriers owned by GasLog Partners (in which we hold the controlling general partner interest as well as limited partner interests) and its subsidiaries and Egypt LNG Shipping Ltd. (in which we hold a 25.0% equity interest); and "Samsung" refers to Samsung Heavy Industries Co., Ltd., or, in each case, one or more of their subsidiaries or to such entities collectively; "NYSE" refers to the New York Stock Exchange; "SEC" refers to the U.S. Securities and Exchange Commission; "dollars" and "$" refers to, and amounts are presented in, U.S. dollars; "Lepta Shipping" refers to Lepta Shipping Co., Ltd.; and "Mitsui" refers to Mitsui & Co., Ltd.

We are an international owner, operator and manager of LNG carriers providing support to international energy companies as part of their LNG logistics chain. As of March 12, 2019, our owned fleet consists of 35 LNG carriers, including 26 ships on the water and nine LNG carriers on order at one of the world's leading LNG shipbuilders, Samsung. This includes 14 LNG carriers in operation that are owned by our NYSE-listed subsidiary GasLog Partners, with which we have entered into certain agreements governing our relationship, including purchase options for certain of our ships. We currently manage and operate 26 LNG carriers including 11 of our wholly owned ships in operation, 13 ships contributed or sold to the Partnership (one is managed by a subsidiary of Shell), one additional LNG carrier in which we have a 25.0% interest and a vessel secured under a long-term bareboat charter from Lepta Shipping, a subsidiary of Mitsui. We are also supervising the construction of our newbuildings. We have secured multi-year contracts for six of our owned ships, the 13 of the 14 ships owned by the Partnership, seven of our nine newbuildings on order and the one vessel secured under a long-term bareboat charter with Lepta Shipping. As of December 31, 2018, these contracts are expected to provide total contracted revenues of $3.6 billion during their initial terms, which expire between 2019 and 2029.

Our wholly owned subsidiary, GasLog LNG Services, exclusively handles the technical management of our fleet, including plan approval for new ship orders, supervision of ship construction and planning and supervision of dry-dockings, as well as technical operations, crewing, training, maintenance, regulatory and classification compliance and health, safety, security and environmental management and reporting. With over 18 years of technical management experience, including 15 years as sole technical manager of BG Group plc's owned fleet of LNG carriers, we have established a track record for the efficient, safe and reliable operation of LNG carriers which is evidenced by our safety performance and the limited off-hire days of the 25 ships currently operating under our management.

On April 4, 2012, we completed an initial public offering and a concurrent private placement of our common shares. On January 22, 2014, we completed a follow-on public offering and concurrent private placement of our common shares. On April 16, 2014, we completed a second follow-on public offering of our common shares. Our common shares are listed on the NYSE under the ticker symbol "GLOG". If any securities are to be listed or quoted on any other securities exchange or quotation system, the applicable prospectus supplement will so state.

On April 7, 2015, we completed a public offering of our Series A Preference Shares, par value $0.01 per share. The Series A Preference Shares are listed on the NYSE under the ticker symbol "GLOG PR A".

On March 22, 2017, we completed a public offering of $250.0 million aggregate principal amount of 8.875% senior unsecured notes due in 2022 (the "8.875% Senior Notes") at a public offering price of 100% of the principal amount. The net proceeds from the offering after deducting the underwriting discount and offering expenses were $245.3 million.

Investing in the securities to be offered pursuant to this prospectus may involve a high degree of risk. You should carefully consider the important factors set forth under the heading "Risk Factors" in our most recent Annual Report on Form 20-F filed with the SEC and incorporated herein by reference and in the accompanying prospectus supplement for such issuance before investing in any securities that may be offered. For further details, see the section entitled "Where You Can Find Additional Information".

Any of the risk factors referred to above could significantly and negatively affect our business, results of operations or financial condition, which may reduce our ability to pay dividends and lower the trading price of our securities. The risks referred to above are not the only ones that may exist. Additional risks not currently known by us or risks that we deem immaterial may also impair our business operations. You may lose all or a part of your investment.

We are a Bermuda exempted company. Our registered address in Bermuda is Clarendon House, 2 Church Street, Hamilton, HM 11, Bermuda. As a result, the rights of holders of our securities will be governed by Bermuda law and our memorandum of association and bye-laws. The rights of shareholders under Bermuda law may differ from the rights of shareholders of companies incorporated in other jurisdictions.

A majority of our directors and some of the named experts referred to in this prospectus are not residents of the United States, and a substantial portion of our assets are located outside the United States. As a result, it may be difficult for investors to effect service of process on those persons in the United States or to enforce in the United States judgments obtained in U.S. courts against us or those persons based on the civil liability provisions of the U.S. securities laws. It is doubtful whether courts in Bermuda will enforce judgments obtained in other jurisdictions, including the United States, against us or our directors or officers under the securities laws of those jurisdictions or entertain actions in Bermuda against us or our directors or officers under the securities laws of other jurisdictions.

However, we have expressly submitted to the jurisdiction of the U.S. federal and New York state courts sitting in the City of New York for the purpose of any suit, action or proceeding arising under the securities laws of the United States or any state in the United States, and we have appointed Puglisi & Associates, 850 Library Avenue, Suite 204, Newark, Delaware 19711, our registered agent, to accept service of process on our behalf in any such action.

This prospectus is part of a registration statement that we filed with the SEC using a shelf registration process. Under this shelf registration process, we may, from time to time, sell up to an aggregate public offering price of $600,000,000 of any combination of the securities described in this prospectus in one or more offerings. This prospectus provides you with a general description of the securities we may offer. Each time we sell securities, we will provide you with this prospectus, as well as a prospectus supplement that will contain specific information about the terms of that offering. That prospectus supplement may include additional risk factors or other special considerations applicable to those particular securities. Any prospectus supplement may also add, update or change information contained in this prospectus. If there is any inconsistency between the information contained in this prospectus and any prospectus supplement, you should rely on the information contained in that particular prospectus supplement. You should read both this prospectus and any prospectus supplement together with additional information described under the heading "Incorporation of Certain Information by Reference" and "Where You Can Find Additional Information".

We have filed with the SEC a registration statement on Form F-3 under the Securities Act of 1933, as amended, with respect to the offer and sale of securities pursuant to this prospectus. For purposes of this section, the term "registration statement" means the original registration statement and any and all amendments, including the schedules and exhibits to the original registration statement and any amendments. This prospectus, filed as a part of the registration statement, does not contain all of the information set forth in the registration statement or the exhibits and schedules thereto in accordance with the rules and regulations of the SEC and no reference is hereby made to such omitted information. Statements made in this prospectus concerning the contents of any contract, agreement or other document filed as an exhibit to the registration statement are summaries of all of the material terms of such contracts, agreements or documents, but do not repeat all of their terms. Reference is made to each such exhibit for a more complete description of the matters involved and such statements shall be deemed qualified in their entirety by such reference. The SEC maintains a website at http://www.sec.gov that contains reports, proxy and information statements and other information regarding registrants that file electronically with the SEC. For further information pertaining to the securities offered by this prospectus and GasLog Ltd., reference is made to the registration statement.

The SEC allows us to "incorporate by reference" information that we file with the SEC. This means that we can disclose important information to you by referring you to those filed documents. The information incorporated by reference is considered to be a part of this prospectus, and information that we file later with the SEC prior to the termination of this offering will also be considered to be part of this prospectus and will automatically update and supersede previously filed information, including information contained in this prospectus.

We are also incorporating by reference all subsequent annual reports on Form 20-F that we file with the SEC and certain reports on Form 6-K that we furnish to the SEC after the date of this prospectus (if they state that they are incorporated by reference into this prospectus) until we file a post- effective amendment indicating that the offering of the securities made by this prospectus has been terminated. In all cases, you should rely on the later information over different information included in this prospectus or any accompanying prospectus supplement.

In accordance with Rule 402 of Regulation S-T, the XBRL-related information in Exhibit 101 to our Annual Report on Form 20-F and our reports on Form 6-K will not be deemed to be incorporated by reference into any registration statement or other document filed under the Securities Act of 1933, as amended, except as will be expressly set forth by specific reference in such filing.

We will provide, free of charge upon written or oral request, to each person to whom this prospectus is delivered, including any beneficial owner of the securities, a copy of any or all of the information that has been incorporated by reference into this prospectus, but which has not been delivered with the prospectus. Copies of these documents also may be obtained on the "Investor Relations" section of our website at www.gaslogltd.com. The information contained on or connected to our website is not a part of this prospectus. Requests for such information should be made to us at the following address:

GasLog Ltd.
c/o GasLog Monaco S.A.M.
Gildo Pastor Center
7 Rue du Gabian
MC 98000, Monaco
+377 97 97 51 15
Attention: General Counsel

You should assume that the information appearing in this prospectus and any accompanying prospectus supplement, as well as the information we previously filed with the SEC and incorporated by reference, is accurate as of the dates on the front cover of those documents only. Our business, financial condition and results of operations and prospects may have changed since those dates.

Unless otherwise set forth in the applicable prospectus supplement, we intend to use the net proceeds received from the sale of the securities we offer by this prospectus for general corporate purposes.

We may raise additional funds from time to time through equity or debt financings not involving the issuance of securities described in this prospectus, including borrowings under credit facilities, to finance our business and operations and new vessel acquisitions.

Our capitalization and indebtedness will be set forth in a prospectus supplement to this prospectus or in a report on Form 6-K subsequently furnished to the SEC and specifically incorporated herein by reference.

More information on our share capital is included under "Item 10. Additional Information" in our annual report on Form 20-F for the year ended December 31, 2018, filed with the SEC on March 5, 2019.

A description of our common shares can be found in our registration statement on Form 8-A (File No. 001-35466), filed with the SEC on March 21, 2012, including any amendment or report filed for the purpose of updating such description.

A description of our Series A Preference Shares can be found in our registration statement on Form 8-A (File No. 001-35466), filed with the SEC on March 31, 2015, including any amendment or report filed for the purpose of updating such description.

Our bye-laws authorize our board of directors to establish one or more series of preference shares, in addition to the Series A Preference Shares, and to determine, with respect to any series of preference shares, the terms and rights of that series. The issuance of preference shares may have the effect of discouraging, delaying or preventing a change of control of us or the removal of our management. The issuance of preference shares with voting and conversion rights may adversely affect the voting power of the holders of shares of our common shares.

The applicable prospectus supplement will describe the following terms of any series of preference shares in respect of which this prospectus is being delivered:

The description in the applicable prospectus supplement of any preference shares we offer will not necessarily be complete and will be qualified in its entirety by reference to the applicable board resolution, certificate of designations or specimen share certificate, which will be filed with the SEC if we offer preference shares. For more information on how you can obtain copies of any board resolution, certificate of designations or specimen share certificate if we offer preference shares, see "Where You Can Find Additional Information" beginning on page 4 of this prospectus. We urge you to read the applicable board resolution, applicable certificate of designations or the applicable specimen share certificate, and any applicable prospectus supplement in their entirety.

We may issue debt securities from time to time in one or more series, under one or more indentures, each dated as of a date on or prior to the issuance of the debt securities to which it relates. We may issue debt securities from time to time in series under an indenture dated March 22, 2017, between us and American Stock Transfer & Trust Company, LLC, as trustee, which is filed as Exhibit 4.1 to our Form 6-K filed with the SEC on March 22, 2017, or a separate indenture.

The following description of debt securities sets forth the material terms and provisions of the debt securities to which any prospectus supplement may relate. The debt securities we may offer may be convertible into common shares or other securities. The indenture, a form of which is included as an exhibit to the registration statement of which this prospectus is a part, will be executed at the time we issue any debt securities. Any supplemental indentures will be filed with the SEC on a Form 6-K or by a post-effective amendment to the registration statement of which this prospectus is a part.

The particular terms of the debt securities offered by any prospectus supplement, and the extent to which the general provisions described below may apply to the offered debt securities, will be described in the applicable prospectus supplement. The indenture will be qualified under the Trust Indenture Act of 1939, as amended (the "Trust Indenture Act"). The terms of the debt securities will include those stated in the indenture and those made part of the indenture by reference to the Trust Indenture Act.

Because the following summaries of the material terms and provisions of the indenture and the related debt securities are not complete, you should refer to the form of the indenture and the debt securities for complete information on some of the terms and provisions of the indenture, including definitions of some of the terms used below, and the debt securities.

The provisions of the indenture do not limit the aggregate principal amount of debt securities which may be issued thereunder. Unless otherwise provided in a prospectus supplement, the debt securities will be our direct, unsecured and unsubordinated general obligations and will have the same rank in liquidation as all of our other unsecured and unsubordinated debt. The debt securities may be convertible into common shares or other securities if specified in the applicable prospectus supplement.

We may issue debt securities from time to time in one or more series. The provisions of the indenture allow us to "reopen" a previous issue of a series of debt securities and issue additional debt securities of that series. The debt securities may be denominated and payable in U.S. dollars or other currencies. We may also issue debt securities from time to time with the principal amount or interest payable on any relevant payment date to be determined by reference to one or more currency exchange rates, securities or baskets of securities, commodity prices or indices. Holders of these types of debt securities will receive payments of principal or interest that depend upon the value of the applicable currency, security or basket of securities, commodity or index on the relevant payment dates.

Debt securities may bear interest at a fixed rate, which may be zero, a floating rate, or a rate which varies during the lifetime of the debt security. Debt securities bearing no interest or interest at a rate that at the time of issuance is below the prevailing market rate may be sold at a discount below their stated principal amount.

The applicable prospectus supplement will contain, where applicable, the following terms of, and other information relating to, any offered debt securities:

Some of the debt securities may be issued as original issue discount securities. Original issue discount securities bear no interest or bear interest at below-market rates and may be sold at a discount below their stated principal amount. The applicable prospectus supplement will contain information relating to income tax, accounting, and other special considerations applicable to original issue discount securities.

Holders may present debt securities for exchange, and holders of registered debt securities may present these securities for transfer, in the manner, at the places and subject to the restrictions stated in the debt securities and described in the applicable prospectus supplement. We will provide these services without charge except for any tax or other governmental charge payable in connection with these services and subject to any limitations or requirements provided in the indenture or the supplemental indenture or issuer order under which that series of debt securities is issued. Holders may transfer debt securities in bearer form and/or the related coupons, if any, by delivery to the transferee. If any of the securities are held in global form, the procedures for transfer of interests in those securities will depend upon the procedures of the depositary for those global securities.

The indenture provides holders of debt securities with remedies if we fail to perform specific obligations, such as making payments on the debt securities, or if we become bankrupt. Holders should review these provisions and understand which actions trigger an event of default and which actions do not. The indenture permits the issuance of debt securities in one or more series, and, in many cases, whether an event of default has occurred is determined on a series-by-series basis.

An event of default is defined under the indenture, with respect to any series of debt securities issued under the indenture, as any one or more of the following events, subject to modification in a supplemental indenture, each of which we refer to in this prospectus as an event of default, having occurred and be continuing:

The indenture provides that, unless otherwise set forth in a supplemental indenture:

In some circumstances, if any and all events of default under the indenture, other than the non-payment of the principal of the securities that has become due as a result of an acceleration, have been cured, waived or otherwise remedied, then the holders of a majority in aggregate principal amount of all series of outstanding debt securities affected, voting as one class, may annul past declarations of acceleration or waive past defaults of the debt securities.

The indenture provides that the trustee shall not be liable with respect to any action taken or omitted to be taken by it in good faith in accordance with the direction of the holders of debt securities issued under the indenture relating to the time, method and place of conducting any proceeding for any remedy available to the trustee, or exercising any trust or power conferred upon the trustee. In addition, the indenture contains a provision entitling the trustee, subject to the duty of the trustee to act with the required standard of care during a default, to be indemnified to its satisfaction by the holders of debt securities issued under the indenture before proceeding to exercise any right or power at the request of holders. Subject to these provisions and specified other limitations, the holders of a majority in aggregate principal amount of each series of outstanding debt securities of each affected series, voting as one class, may direct the time, method and place of conducting any proceeding for any remedy available to the trustee, or exercising any trust or power conferred on the trustee.

The indenture provides that no individual holder of debt securities may institute any action against us under the indenture, except actions for payment of overdue principal and interest, unless the following actions have occurred:

The indenture contains a covenant that we will file annually with the trustee a certificate of no default or a certificate specifying any default that exists.

We have the ability to eliminate most or all of our obligations on any series of debt securities prior to maturity if we comply with the following provisions:

Discharge of Indenture. We may discharge all of our obligations, other than as to transfers and exchanges, under the indenture after we have:

Defeasance of a Series of Securities at Any Time. We may also discharge all of our obligations, other than as to transfers and exchanges, under any series of debt securities at any time, which we refer to as defeasance in this prospectus. We may be released with respect to any outstanding series of debt securities from the obligations imposed by any covenants and elect not to comply with those covenants without creating an event of default. Discharge under those procedures is called covenant defeasance.

Modification without Consent of Holders. We and the trustee may enter into supplemental indentures without the consent of the holders of debt securities issued under the indenture to:

Modification with Consent of Holders. We and the trustee, with the consent of the holders of not less than a majority in aggregate principal amount of each affected series of outstanding debt securities, voting as one class, may add any provisions to, or change in any manner or eliminate any of the provisions of, the indenture or modify in any manner the rights of the holders of those debt securities. However, we and the trustee may not make any of the following changes to any outstanding debt security without the consent of each holder that would be affected by the change:

Each debt security will be represented either by a certificate issued in definitive form to a particular investor or by one or more global securities representing the entire issuance of securities. Both certificated securities in definitive form and global securities may be issued either:

Definitive securities name you or your nominee as the owner of the security, other than definitive bearer securities, which name the bearer as owner, and in order to transfer or exchange these securities or to receive payments other than interest or other interim payments, you or your nominee must physically deliver the securities to the trustee, registrar, paying agent or other agent, as applicable.

Global securities name a depositary or its nominee as the owner of the debt securities represented by these global securities, other than global bearer securities, which name the bearer as owner. The depositary maintains a computerized system that will reflect each investor's beneficial ownership of the securities through an account maintained by the investor with its broker/dealer, bank, trust company or other representative, as we explain more fully below.

Registered Global Securities. We may issue the debt securities in the form of one or more fully registered global securities that will be deposited with a depositary or its nominee identified in the applicable prospectus supplement and registered in the name of that depositary or nominee. In those cases, one or more registered global securities will be issued in a denomination or aggregate denominations equal to the portion of the aggregate principal or face amount of the securities to be represented by registered global securities. Unless and until it is exchanged in whole for securities in definitive registered form, a registered global security may not be transferred except as a whole by and among the depositary for the registered global security, the nominees of the depositary or any successors of the depositary or those nominees. If not described below, any specific terms of the depositary arrangement with respect to any securities to be represented by a registered global security will be described in the prospectus supplement relating to those securities. We anticipate that the following provisions will apply to all depositary arrangements:

Ownership of beneficial interests in a registered global security will be limited to persons, called participants, that have accounts with the depositary or persons that may hold interests through participants. Upon the issuance of a registered global security, the depositary will credit, on its book-entry registration and transfer system, the participants' accounts with the respective principal or face amounts of the securities beneficially owned by the participants. Any dealers, underwriters or selling agents participating in the distribution of the securities will designate the accounts to be credited. Ownership of beneficial interests in a registered global security will be shown on, and the transfer of ownership interests will be effected only through, records maintained by the depositary, with respect to interests of participants, and on the records of participants, with respect to interests of persons holding through participants. The laws of some jurisdictions may require that some purchasers of securities take physical delivery of these securities in definitive form. These laws may impair your ability to own, transfer or pledge beneficial interests in registered global securities. So long as the depositary, or its nominee, is the registered owner of a registered global security, that depositary or its nominee, as the case may be, will be considered the sole owner or holder of the securities represented by the registered global security for all purposes under the indenture.

Except as described below, owners of beneficial interests in a registered global security will not be entitled to have the securities represented by the registered global security registered in their names, will not receive or be entitled to receive physical delivery of the securities in definitive form and will not be considered the owners or holders of the securities under the indenture. Accordingly, each person owning a beneficial interest in a registered global security must rely on the procedures of the depositary for that registered global security and, if that person is not a participant, on the procedures of the participant through which the person owns its interest, to exercise any rights of a holder under the indenture. We understand that under existing industry practices, if we request any action of holders or if an owner of a beneficial interest in a registered global security desires to give or take any action that a holder is entitled to give or take under the indenture, the depositary for the registered global security would authorize the participants holding the relevant beneficial interests to give or take that action, and the participants would authorize beneficial owners owning through them to give or take that action or would otherwise act upon the instructions of beneficial owners holding through them.

Principal, premium, if any, and interest payments on debt securities represented by a registered global security registered in the name of a depositary or its nominee will be made to the depositary or its nominee, as the case may be, as the registered owner of the registered global security. None of us, the trustee or any other agent of us or agent of the trustee will have any responsibility or liability for any aspect of the records relating to payments made on account of beneficial ownership interests in the registered global security or for maintaining, supervising or reviewing any records relating to those beneficial ownership interests. We expect that the depositary for any of the securities represented by a registered global security, upon receipt of any payment of principal, premium, interest or other distribution of underlying securities or other property to holders on that registered global security, will immediately credit participants' accounts in amounts proportionate to their respective beneficial interests in that registered global security as shown on the records of the depositary. We also expect that payments by participants to owners of beneficial interests in a registered global security held through participants will be governed by standing customer instructions and customary practices, as is now the case with the securities held for the accounts of customers in bearer form or registered in "street name", and will be the responsibility of those participants.

If the depositary for any of these securities represented by a registered global security is at any time unwilling or unable to continue as depositary or ceases to be a clearing agency registered under the Exchange Act, and a successor depositary registered as a clearing agency under the Exchange Act is not appointed by us within 90 days, we will issue securities in definitive form in exchange for the registered global security that had been held by the depositary. In addition, we may, at any time and in our sole discretion, decide not to have any of the securities represented by one or more registered

global securities. If we make that decision, we will issue securities in definitive form in exchange for all of the registered global security or securities representing those securities. Any securities issued in definitive form in exchange for a registered global security will be registered in the name or names that the depositary gives to the relevant trustee or other relevant agent of ours or theirs. It is expected that the depositary's instructions will be based upon directions received by the depositary from participants with respect to ownership of beneficial interests in the registered global security that had been held by the depositary.

Bearer Global Securities. The securities may also be issued in the form of one or more bearer global securities that will be deposited with a common depositary for the Euroclear System and Clearstream Banking, société anonyme or with a nominee for the depositary identified in the prospectus supplement relating to those securities. The specific terms and procedures, including the specific terms of the depositary arrangement, with respect to any securities to be represented by a bearer global security will be described in the prospectus supplement relating to those securities.

The indenture and the debt securities will be governed by the laws of the State of New York.

We may issue warrants to purchase our equity securities or securities of third parties or other rights, including rights to receive payment in cash or securities based on the value, rate or price of one or more specified commodities, currencies, securities or indices, or any combination of the foregoing. Warrants may be issued independently or together with any other securities and may be attached to, or separate from, such securities. A series of warrants may be issued under a separate warrant agreement to be entered into between us and a warrant agent. The terms of any warrants to be issued and a description of the material provisions of any applicable warrant agreement will be set forth in the applicable prospectus supplement.

The applicable prospectus supplement will describe the following terms of any warrants in respect of which this prospectus is being delivered:

The description in the applicable prospectus supplement of any warrants we offer will not necessarily be complete and will be qualified in its entirety by reference to the applicable warrant certificate or warrant agreement, which will be filed with the SEC if we offer warrants. For more information on how you can obtain copies of any warrant certificate or warrant agreement if we offer warrants, see "Where You Can Find Additional Information" beginning on page 4 of this prospectus. We urge you to read the applicable warrant certificate, the applicable warrant agreement and any applicable prospectus supplement in their entirety.

We may issue rights to purchase our equity securities. These rights may be issued independently or together with any other security offered by this prospectus and may or may not be transferable by the shareholder receiving the rights in the rights offering. In connection with any rights offering, we may enter into a standby underwriting agreement with one or more underwriters pursuant to which the underwriter will purchase any securities that remain unsubscribed for upon completion of the rights offering.

The applicable prospectus supplement relating to any rights will describe the terms of the offered rights, including, where applicable, the following:

The description in the applicable prospectus supplement of any rights we offer will not necessarily be complete and will be qualified in its entirety by reference to the applicable rights certificate or rights agreement, which will be filed with the SEC if we offer rights. For more information on how you can obtain copies of any rights certificate or rights agreement if we offer rights, see "Where You Can Find Additional Information" beginning on page 4 of this prospectus. We urge you to read the applicable rights certificate, the applicable rights agreement and any applicable prospectus supplement in their entirety.

We may issue units consisting of any combination of common shares, preference shares, Series A Preference Shares, debt securities, warrants and rights. Each unit will be issued so that the holder of the unit is also the holder of each security included in the unit. Thus, the holder of a unit will have the rights and obligations of a holder of each included security. The unit agreement under which a unit is issued may provide that the securities included in the unit may not be held or transferred separately, at any time, or at any time before a specified date.

The applicable prospectus supplement relating to any series of units will describe the terms of the units, including, where applicable, the following:

The description in the applicable prospectus supplement of any units we offer will not necessarily be complete and will be qualified in its entirety by reference to the applicable unit certificate or unit agreement, which will be filed with the SEC if we offer units. For more information on how you can obtain copies of any unit certificate or unit agreement if we offer units, see "Where You Can Find Additional Information" beginning on page 4 of this prospectus. We urge you to read the applicable unit certificate, the applicable unit agreement and any applicable prospectus supplement in their entirety.

Our Annual Report filed on Form 20-F provides a discussion of the material U.S. federal income tax considerations that may be relevant to prospective investors in our securities. The applicable prospectus supplement may also contain information about any material U.S. federal income tax considerations relating to the securities covered by such prospectus supplement.

Our Annual Report filed on Form 20-F provides a discussion of Bermuda tax consequences that may be relevant to prospective investors in our securities. The applicable prospectus supplement may also contain information about any non-U.S. tax considerations relating to the securities covered by such prospectus supplement.

We may offer and sell, from time to time, the securities covered by this prospectus and the applicable prospectus supplement. We have registered the securities covered by this prospectus for offer and sale so that those securities may be freely sold to the public. Registration of the securities covered by this prospectus does not mean, however, that those securities necessarily will be offered or sold.

Securities covered by this prospectus may be sold from time to time, in one or more transactions, at market prices prevailing at the time of sale, at prices related to market prices, at a fixed price or

prices subject to change, at varying prices determined at the time of sale or at negotiated prices, by a variety of methods including the following:

In effecting sales, brokers or dealers engaged by us may arrange for other brokers or dealers to participate. Broker-dealer transactions may include:

In addition, we may sell any securities covered by this prospectus in private transactions or under Rule 144 of the Securities Act of 1933, as amended, rather than pursuant to this prospectus.

In connection with the sale of securities covered by this prospectus, broker-dealers may receive commissions or other compensation from us in the form of commissions, discounts or concessions. Broker-dealers may also receive compensation from purchasers of the securities for whom they act as agents or to whom they sell as principals or both. Compensation as to a particular broker-dealer may be in excess of customary commissions or in amounts to be negotiated. In connection with any underwritten offering, underwriters may receive compensation in the form of discounts, concessions or commissions from us or from purchasers of the securities for whom they act as agents. Underwriters may sell the securities to or through dealers, and such dealers may receive compensation in the form of discounts, concessions or commissions from the underwriters and/or commissions from the purchasers for whom they may act as agents. Any underwriters, broker-dealers or agents that participate in the

distribution of the securities may be deemed to be "underwriters" within the meaning of the Securities Act of 1933, as amended, and any profit on the sale of the securities by them and any discounts, commissions or concessions received by any of those underwriters, broker-dealers or agents may be deemed to be underwriting discounts and commissions under the Securities Act of 1933, as amended.

In connection with the distribution of the securities covered by this prospectus or otherwise, we may enter into hedging transactions with broker-dealers or other financial institutions. In connection with such transactions, broker-dealers or other financial institutions may engage in short sales of our securities in the course of hedging the positions they assume with us. We may also sell securities short and deliver the securities offered by this prospectus to close out our short positions. We may also enter into option or other transactions with broker-dealers or other financial institutions, which require the delivery to such broker-dealer or other financial institution of securities offered by this prospectus, which securities such broker-dealer or other financial institution may resell pursuant to this prospectus, as supplemented or amended to reflect such transaction. We may also from time to time pledge securities pursuant to the margin provisions of any customer agreements with brokers. Upon default, the broker may offer and sell such pledged securities from time to time pursuant to this prospectus, as supplemented or amended to reflect such transaction.

At any time a particular offer of the securities covered by this prospectus is made, a revised prospectus or prospectus supplement, if required, will be distributed which will set forth the aggregate amount of securities covered by this prospectus being offered and the terms of the offering, including the expected issue price or method of determining the price, the time period during which the offer will be open and whether the purchase period may be extended or shortened, the method and time limits for paying up and delivering securities, name or names of any underwriters, dealers, brokers or agents, any discounts, commissions, concessions and other items constituting compensation from us, and any discounts, commissions or concessions allowed or reallowed or paid to dealers. Such prospectus supplement, and, if necessary, a post-effective amendment to the registration statement of which this prospectus is a part, will be filed with the SEC to reflect the disclosure of additional information with respect to the distribution of the securities covered by this prospectus. In order to comply with the securities laws of certain states, if applicable, the securities sold under this prospectus may only be sold through registered or licensed broker-dealers. In addition, in some states the securities may not be sold unless they have been registered or qualified for sale in the applicable state or an exemption from registration or qualification requirements is available and is complied with.

In connection with an underwritten offering, we would execute an underwriting agreement with an underwriter or underwriters. Unless otherwise indicated in the revised prospectus or applicable prospectus supplement, such underwriting agreement would provide that the obligations of the underwriter or underwriters are subject to certain conditions precedent and that the underwriter or underwriters with respect to a sale of the covered securities will be obligated to purchase all of the covered securities if any such securities are purchased. We may grant to the underwriter or underwriters an option to purchase additional securities at the public offering price, as may be set forth in the revised prospectus or applicable prospectus supplement. If we grant any such option, the terms of the option will be set forth in the revised prospectus or applicable prospectus supplement.

Pursuant to a requirement by the Financial Industry Regulatory Authority, or "FINRA", if more than five percent of the net proceeds of any offering of securities made under this prospectus will be received by any FINRA member participating in the offering or by affiliates or associated persons of such FINRA member or any participating member who otherwise would have a "conflict of interest" under FINRA Rules, the offering will be conducted in accordance with FINRA Rule 5121.

Underwriters, agents, brokers or dealers may be entitled, pursuant to relevant agreements entered into with us, to indemnification by us against certain civil liabilities, including liabilities under the Securities Act of 1933, as amended, that may arise from any untrue statement or alleged untrue

statement of a material fact, or any omission or alleged omission to state a material fact in this prospectus, any supplement or amendment hereto, or in the registration statement of which this prospectus forms a part, or to contribution with respect to payments which the underwriters, agents, brokers or dealers may be required to make.

We will bear all costs relating to all of the securities being registered under the registration statement of which this prospectus is a part.

The following are the expenses estimated to be incurred by us in connection with a possible offering of the securities registered under this registration statement.

The validity of the securities that may be offered by this prospectus and certain other matters relating to Bermuda law will be passed upon for us by Conyers Dill & Pearman Limited, Bermuda. Certain other legal matters relating to United States law will be passed upon for us by Cravath, Swaine & Moore LLP, New York, New York.

The consolidated financial statements of GasLog Ltd. as of December 31, 2018 and December 31, 2017, and for each of the years in the three-year period ended December 31, 2018, incorporated in this prospectus by reference from the Company's Annual Report on Form 20-F for the year ended December 31, 2018 and the effectiveness of GasLog Ltd.'s internal control over financial reporting as of December 31, 2018, have been audited by Deloitte LLP, an independent registered public accounting firm, as stated in their reports, which are incorporated herein by reference. Such consolidated financial statements have been so incorporated in reliance upon the report of such firm, given upon their authority as experts in accounting and auditing.

The offices of Deloitte LLP are located at 2 New Street Square, London, EC4A 3BZ, United Kingdom.

	Per Additional Note	Total




Public Offering Price⁽¹⁾	$	$

Underwriting Discounts and Commissions⁽²⁾	$	$

Proceeds to GasLog Ltd. (before expenses)	$	$

		Page

PROSPECTUS SUPPLEMENT
SUMMARY		S-1
RISK FACTORS		S-15
FORWARD-LOOKING STATEMENTS		S-20
USE OF PROCEEDS		S-22
CAPITALIZATION		S-23
DESCRIPTION OF OTHER INDEBTEDNESS		S-25
DESCRIPTION OF NOTES		S-28
MATERIAL TAX CONSIDERATIONS.		S-53
OTHER EXPENSES OF ISSUANCE AND DISTRIBUTION		S-59
UNDERWRITING		S-60
SERVICE OF PROCESS AND ENFORCEMENT OF LIABILITIES		S-64
LEGAL MATTERS		S-64
EXPERTS		S-64
WHERE YOU CAN FIND ADDITIONAL INFORMATION		S-64
INCORPORATION OF CERTAIN INFORMATION BY REFERENCE		S-65



PROSPECTUS
FORWARD LOOKING STATEMENTS		1
THE COMPANY		3
RISK FACTORS		5
SERVICE OF PROCESS AND ENFORCEMENT OF LIABILITIES		6
ABOUT THIS PROSPECTUS		7
WHERE YOU CAN FIND ADDITIONAL INFORMATION		7
INCORPORATION OF CERTAIN INFORMATION BY REFERENCE		8
USE OF PROCEEDS		9
CAPITALIZATION AND INDEBTEDNESS		9
DESCRIPTION OF SHARE CAPITAL		9
DESCRIPTION OF PREFERENCE SHARES		9
DESCRIPTION OF DEBT SECURITIES		11
DESCRIPTION OF WARRANTS		19
DESCRIPTION OF RIGHTS		20
DESCRIPTION OF THE UNITS		21
MATERIAL U.S. FEDERAL INCOME TAX CONSIDERATIONS		21
NON-UNITED STATES TAX CONSIDERATIONS		21
PLAN OF DISTRIBUTION		21
EXPENSES		24
LEGAL MATTERS		24
EXPERTS		24


SEC Registration Fee^*	$	9,090
Printing		40,000
Legal Fees and Expenses		300,000
Accountants' Fees and Expenses		60,000
Transfer Agent Fees and Expenses		10,000
Miscellaneous Costs		10,910

Total	$	430,000


FORWARD-LOOKING STATEMENTS		1
THE COMPANY		3
RISK FACTORS		5
SERVICE OF PROCESS AND ENFORCEMENT OF LIABILITIES		6
ABOUT THIS PROSPECTUS		7
WHERE YOU CAN FIND ADDITIONAL INFORMATION		7
INCORPORATION OF CERTAIN INFORMATION BY REFERENCE		8
USE OF PROCEEDS		9
CAPITALIZATION AND INDEBTEDNESS		9
DESCRIPTION OF SHARE CAPITAL		9
DESCRIPTION OF PREFERENCE SHARES		9
DESCRIPTION OF DEBT SECURITIES		11
DESCRIPTION OF WARRANTS		19
DESCRIPTION OF RIGHTS		20
DESCRIPTION OF THE UNITS		21
MATERIAL U.S. FEDERAL INCOME TAX CONSIDERATIONS		21
NON-UNITED STATES TAX CONSIDERATIONS		21
PLAN OF DISTRIBUTION		21
EXPENSES		24
LEGAL MATTERS		24
EXPERTS		24

Underwriter		Principal Amount

Credit Suisse Securities (USA) LLC		$
DNB Markets, Inc		$
Stifel, Nicolaus & Company, Incorporated		$

Total		$


SEC Registration Fee	$	30,300
Printing			*
Legal Fees and Expenses.			*
Accountants' Fees and Expenses			*
NYSE Fees			*
Miscellaneous Costs			*

Total	$		*


Credit Suisse		DNB Markets		Stifel


Credit Suisse		DNB Markets		Stifel