UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No. 5)*

Tesoro Logistics LP

(Name of Issuer)

Common Units

(Title of Class of Securities)

88160T107

(CUSIP Number)

David L. Ronn

McGuireWoods LLP

600 Travis Street, Suite 7500

Houston, Texas 77002-2906

(713) 353-6671

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

November 12, 2015

(Date of Event Which Requires Filing of This Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because § 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g) check the following box.  ¨

Note: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See Rule 13d-7 for other parties to whom copies are to be sent.

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act.

Explanatory Note: This Amendment No. 5 (this “Amendment”) amends and supplements the statement on Schedule 13D filed by Tesoro Corporation (“Tesoro”), Tesoro Refining and Marketing Company (“TRMC”), Tesoro Alaska Company LLC (“Tesoro Alaska”) and Tesoro Logistics GP, LLC (the “General Partner” and, collectively with Tesoro, TRMC and Tesoro Alaska, the “Reporting Persons”) on September 24, 2012, as amended on June 3, 2013, December 9, 2013, May 20, 2014 and October 24, 2014 (the “Initial Statement”). The Initial Statement shall not be modified except as specifically provided herein.

Item 2 of the Initial Statement is hereby supplemented as follows:

The information required by subparagraphs (a), (b), (c) and (f) of this Item with respect to the directors and executive officers of the Reporting Persons is set forth on Schedule A attached hereto and is incorporated herein by reference. Such schedule amends and restates, as to the information required by such subparagraphs, the information contained in Schedule A of the Initial Statement.

Item 3 of the Initial Statement is hereby supplemented as follows:

On November 12, 2015, pursuant to the Contribution, Conveyance and Assumption Agreement among the Issuer, the General Partner, TRMC and the other parties thereto (which is filed as Exhibit 1 hereto and is incorporated herein by reference): (i) Carson Cogen Company, a wholly-owned subsidiary of TRMC, contributed certain assets to the Issuer and in exchange received 151,021 Common Units; and (ii) the General Partner contributed certain assets to the Issuer and in exchange received 4,112,346 Common Units, approximately $250 million in cash, and the number of general partner units necessary to restore and maintain its 2.0% general partner interest in the Issuer.

Item 5(a) of the Initial Statement is supplemented as follows:

Items 11 and 13 of each Cover Page state the aggregate number and percentage of Common Units beneficially owned by the applicable Reporting Persons. Such information is incorporated herein by reference.

As of November 12, 2015, the approximate number of Common Units issued and outstanding is 93,125,182, with such figure provided to the Reporting Persons by the Issuer.

As of November 12, 2015, (i) Tesoro is the record holder of 15,620,925 Common Units, over which it has sole voting and dispositive power; (ii) TRMC is the record holder of 8,067,981 Common Units and the indirect holder of 151,021 Common Units held directly by its wholly-owned subsidiary Carson Cogen, over which it shares voting and dispositive power with Tesoro

due to Tesoro’s ownership of 100% of the securities of TRMC; and (iii) Tesoro Alaska is the record holder of 571,065 Common Units, over which it shares voting and dispositive power with Tesoro due to Tesoro’s ownership of 100% of the securities of Tesoro Alaska.

As of November 12, 2015, the General Partner is the record holder of 8,034,123 Common Units. The General Partner shares voting and dispositive power over these Common Units with Tesoro, TRMC and Tesoro Alaska due to Tesoro’s, TRMC’s and Tesoro Alaska’s ownership of 100% of the General Partner’s membership interests (4%, 95.5% and 0.5%, respectively).

The number of Common Units held by each of the Reporting Persons’ directors and executive officers is set forth on Schedule A and is incorporated herein by reference.

Each of the Reporting Persons disclaims beneficial ownership of the securities held by others, including the other Reporting Persons, except to the extent of such Reporting Persons’ pecuniary interest therein, if any.

The information set forth in Item 3 is incorporated herein by reference.

Item 6. Contracts, Arrangements, Understandings or Relationships with Respect to Securities of the Issuer.

Item 6 of the Initial Statement is supplemented as follows:

On November 12, 2015, pursuant to the Amendment No. 2 to the Second Amended and Restated Limited Liability Company Agreement of Tesoro Logistics GP, LLC, Tesoro and TRMC amended and restated their respective membership interests in the General Partner to account for the capital contributions made by TRMC to the General Partner on that date.

All references to, and descriptions of, the Limited Liability Company Agreement as set forth in this Item 6 are qualified in their entirety by reference to the Second Amended and Restated Limited Liability Company Agreement filed as Exhibit 3.1 to the Issuer’s Current Report on Form 8-K filed on July 1, 2014 and Amendment No. 1 to the Second Amended, Restated Limited Liability Company Agreement filed as Exhibit 3.1 to the Issuer’s Current Report on Form 8-K filed on September 30, 2014, and Amendment No. 2 to the Second Amended, Restated Limited Liability Company Agreement filed as Exhibit 3.1 to the Issuer’s Current Report on Form 8-K filed on November 12, 2015.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Dated: November 12, 2015

SCHEDULE A

DIRECTORS AND EXECUTIVE OFFICERS OF TESORO CORPORATION

The business address of each person listed below is c/o Tesoro Corporation, 19100 Ridgewood Parkway, San Antonio, Texas 78259-1828. Each person is a United States citizen.

Directors:

Executive Officers:

[Schedule A Continues on Next Page]

DIRECTORS AND EXECUTIVE OFFICERS OF

TESORO REFINING & MARKETING COMPANY LLC

The business address of each person listed below is c/o Tesoro Refining & Marketing Company LLC, 19100 Ridgewood Parkway, San Antonio, Texas 78259-1828. Each person is a United States citizen.

Directors:

Executive Officers:

[Schedule A Continues on Next Page]

DIRECTORS AND EXECUTIVE OFFICERS OF TESORO ALASKA COMPANY LLC

The business address of each person listed below is c/o Tesoro Alaska Company LLC, 19100 Ridgewood Parkway, San Antonio, Texas 78259-1828. Each person is a United States citizen.

Directors:

Executive Officers:

[Schedule A Continues on Next Page]

DIRECTORS AND EXECUTIVE OFFICERS OF TESORO LOGISTICS GP, LLC

The business address of each person listed below is c/o Tesoro Logistics GP, LLC, 19100 Ridgewood Parkway, San Antonio, Texas 78259-1828. Each person is a United States citizen.

Directors:

Executive Officers:

[Schedule A Continues on Next Page]

TRANSACTIONS BY THE DIRECTORS AND EXECUTIVE OFFICERS OF THE REPORTING PERSONS

[End of Schedule A]