UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No. 1)*

Endurance International Group Holdings, Inc.

(Name of Issuer)

Common Stock, par value $0.0001 per share

(Title of Class of Securities)

29272B 105

(CUSIP Number)

Hari K. Ravichandran

10 Corporate Drive, Suite 300

Burlington, Massachusetts 01803

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

March 11, 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 of §§240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box.  ¨

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, as amended (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

SCHEDULE 13D

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SCHEDULE 13D

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SCHEDULE 13D

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SCHEDULE 13D

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SCHEDULE 13D

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SCHEDULE 13D

This Amendment No. 1 to the Schedule 13D amends and restates in its entirety the Schedule 13D filed on January 24, 2014 (the “Original Schedule 13D”) by the Reporting Persons (as defined below).

This statement on Schedule 13D (this “Schedule 13D”) relates to the common stock, par value $0.0001 per share (the “Common Stock”), of Endurance International Group Holdings, Inc., a Delaware corporation (the “Issuer”). The address of the Issuer’s principal executive office is 10 Corporate Drive, Suite 300, Burlington, Massachusetts 01803.

(a) This Schedule 13D is being filed by Mr. Hari K. Ravichandran, an individual, and on behalf of the Ravichandran Family LLC, a Delaware limited liability company, The Hari Ravichandran 2013 Grantor Retained Annuity Trust, a trust formed under the laws of the Commonwealth of Massachusetts, The 2013 Ravichandran Family GST Trust, a trust formed under the laws of the state of New Hampshire, and The Hari Ravichandran 2014 Grantor Retained Annuity Trust, a trust formed under the laws of the Commonwealth of Massachusetts (collectively, the “Reporting Persons”).

Mr. Ravichandran owns directly 5,000,315 shares of Common Stock. Caitlin Ravichandran, Mr. Ravichandran’s wife, is the Manager of the Ravichandran Family LLC, of which Mr. Ravichandran owns 90 common units, or 90%. The Ravichandran 2011 Family Trust, an irrevocable trust established by Mr. Ravichandran for his children and more remote issue as part of his estate plan, owns the remaining 10 common units, or 10%, of the Ravichandran Family LLC. Mrs. Ravichandran and Vidya Ravichandran, Mr. Ravichandran’s sister, are the trustees of the Ravichandran 2011 Family Trust. As a result, Mr. Ravichandran may have voting and investment control over, and may be deemed the beneficial owner of, 1,767,747 shares of Common Stock owned by the Ravichandran Family LLC. In addition, Mr. Ravichandran is also the grantor and trustee of The Hari Ravichandran 2013 Grantor Retained Annuity Trust and The Hari Ravichandran 2014 Grantor Retained Annuity Trust and the grantor of The 2013 Ravichandran Family GST Trust, an irrevocable trust established by Mr. Ravichandran for his children and more remote issue as part of his estate plan (together with The Hari Ravichandran 2013 Grantor Retained Annuity Trust and The Hari Ravichandran 2014 Grantor Retained Annuity Trust, the “Ravichandran Trusts”). As a result, Mr. Ravichandran may have voting and investment control over, and may be deemed to be the beneficial owner of, an aggregate of 904,659 shares of Common Stock owned by the Ravichandran Trusts. The number of shares beneficially owned by Mr. Ravichandran also includes 601,552 shares of Common Stock underlying restricted stock units and 1,022,445 shares of Common Stock underlying options to purchase shares of Common Stock, in each case, that have vested as of the date hereof or will become vested within 60 days after such date.

(b) Mr. Ravichandran’s business address is c/o Endurance International Group Holdings, Inc., 10 Corporate Drive, Suite 300, Burlington, Massachusetts 01803. The principal business address of the Ravichandran Family LLC, The Hari Ravichandran 2013 Grantor Retained Annuity Trust and The Hari Ravichandran 2014 Grantor Retained Annuity Trust is c/o Endurance International Group Holdings, Inc., 10 Corporate Drive, Suite 300, Burlington, Massachusetts 01803. The principal business address of The 2013 Ravichandran Family GST Trust is c/o Perspecta Trust LLC, One Liberty Lane E Suite 100, Hampton, New Hampshire 03842.

(c) Mr. Ravichandran is the President and Chief Executive Officer of the Issuer and serves as a member of the board of directors of the Issuer.

(d) None of the Reporting Persons has, during the last five years, been convicted in a criminal proceeding (excluding traffic violations or similar misdemeanors).

(e) None of the Reporting Persons has, during the last five years, been a party to a civil proceeding of a judicial or administrative body of competent jurisdiction as a result of which such Reporting Person was or is subject to a judgment, decree or final order enjoining future violations of, or prohibiting or mandating activities subject to, federal or state securities laws or finding any violation with respect to such laws.

(f) Mr. Ravichandran is a United States citizen.

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SCHEDULE 13D

Shares of Common Stock reported in this Schedule 13D were acquired by Mr. Ravichandran in consideration of his employment with the Issuer at various times since inception of the Issuer and prior to the Issuer becoming a reporting company on October 25, 2013, through the exercise of a portion of the options described below, and through a rollover of previously-held equity interests in a predecessor of the Issuer.

On October 25, 2013, in consideration of his employment with the Issuer, the Issuer granted Mr. Ravichandran restricted stock units for an aggregate of 1,013,342 shares of Common Stock and options to purchase 2,729,188 shares of Common Stock, of which an aggregate of 1,623,997 shares of Common Stock have vested as of the date hereof or will become vested within 60 days after such date and are reported in this Schedule 13D.

The 1,767,747 shares of Common Stock held by Ravichandran Family LLC were acquired through a rollover of previously-held equity interests in a predecessor of the Issuer prior to the Issuer becoming a reporting company on October 25, 2013. Caitlin Ravichandran, Mr. Ravichandran’s wife, is the Manager of the Ravichandran Family LLC, of which Mr. Ravichandran owns 90 common units, or 90%. The Ravichandran 2011 Family Trust, an irrevocable trust established by Mr. Ravichandran for his children and more remote issue as part of his estate plan, owns the remaining 10 common units, or 10%, of the Ravichandran Family LLC. Mrs. Ravichandran and Vidya Ravichandran, Mr. Ravichandran’s sister, are the trustees of the Ravichandran 2011 Family Trust.

The 226,122 shares of Common Stock held by The Hari Ravichandran 2013 Grantor Retained Annuity Trust, of which Mr. Ravichandran is the grantor and trustee, were acquired through a gift from Mr. Ravichandran prior to the Issuer becoming a reporting company on October 25, 2013.

The 217,309 shares of Common Stock held by The 2013 Ravichandran Family GST Trust, an irrevocable trust established by Mr. Ravichandran for his children and more remote issue as part of his estate plan, of which Mr. Ravichandran is the grantor, were acquired through a gift from Mr. Ravichandran prior to the Issuer becoming a reporting company on October 25, 2013.

The 461,228 shares of Common Stock held by The Hari Ravichandran 2014 Grantor Retained Annuity Trust, of which Mr. Ravichandran is the grantor and trustee, were acquired through a gift from Mr. Ravichandran on October 6, 2014.

The information contained in Item 3 above is incorporated herein by reference.

All shares of Common Stock reported as held or acquired by the Reporting Persons in this Schedule 13D were acquired in consideration of Mr. Ravichandran’s employment with the Issuer or for the purpose of investment and were not intended to and did not affect any change in the control of the Issuer.

Mr. Ravichandran is the President and Chief Executive Officer of the Issuer and serves as a member of the board of directors of the Issuer, and in such capacities, Mr. Ravichandran may effect a measure of control over the Issuer and may be involved from time to time in the consideration of matters specified in Item 4 of Schedule 13D on behalf of the Issuer. In addition, Mr. Ravichandran intends to review his investment in the Issuer from time to time and, depending on market conditions and other factors that Mr. Ravichandran may deem material in making his investment decision, Mr. Ravichandran may exercise all or any portion of vested equity awards, make additional purchases or sales of the Issuer’s securities in open market or private transactions, sell all or any portion of the Common Stock hereafter acquired by Mr. Ravichandran in open market or private transactions, or take other steps to increase or decrease his investment in the Issuer.

Except as described above, none of the Reporting Persons currently has any plan or proposal that relates to or would result in any of the actions specified in clauses (a) through (j) of Item 4 of Schedule 13D.

(a) As of the date hereof, Mr. Ravichandran may be deemed the beneficial owner of 7,672,721 shares of Common Stock, representing approximately 5.7% of the Issuer’s currently outstanding Common Stock. Mr. Ravichandran’s ownership consists of (i) 5,000,315 shares of Common Stock held directly by Mr. Ravichandran, including 601,552 shares of Common Stock underlying restricted stock units and 1,022,445 shares of Common Stock underlying options to purchase shares of Common Stock, in each case, that Mr. Ravichandran had the right to acquire as of the date hereof or has the right to acquire within 60 days of such date, (ii) 1,767,747 shares of Common Stock held by the Ravichandran Family LLC, (iii) 226,122 shares of Common Stock held by The Hari Ravichandran

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SCHEDULE 13D

2013 Grantor Retained Annuity Trust, (iv) 217,309 shares of Common Stock held by The 2013 Ravichandran Family GST Trust and (v) 461,228 shares of Common Stock held by The Hari Ravichandran 2014 Grantor Retained Annuity Trust.

As of the date hereof, the Ravichandran Family LLC, The Hari Ravichandran 2013 Grantor Retained Annuity Trust, The 2013 Ravichandran Family GST Trust and The Hari Ravichandran 2014 Grantor Retained Annuity Trust own 1,767,747 shares, 226,122 shares, 217,309 shares and 461,228 shares of Common Stock, respectively, representing approximately 1.3%, 0.2%, 0.2% and 0.4% of the Issuer’s currently outstanding Common Stock.

The percentage ownership of the Issuer’s currently outstanding Common Stock set forth above is based on 132,371,246 shares of Common Stock outstanding as of March 3, 2015, as reported in the Issuer’s Definitive Proxy Statement filed with the Securities and Exchange Commission on March 16, 2015.

(b) With respect to the number of shares of Common Stock as to which each Reporting Person has:

(i) sole power to vote or to direct the vote with respect to such shares of Common Stock, please see row 7 of the applicable cover sheet to this Schedule 13D for such Reporting Person;

(ii) sole power to dispose or direct the disposition of such shares of Common Stock, please see row 9 of the applicable cover sheet to this Schedule 13D for such Reporting Person; and

(iii) shared power to dispose or to direct the disposition of such shares of Common Stock, please see row 10 of the applicable cover sheet to this Schedule 13D for such Reporting Person.

(c) On March 11, 2015, Hari Ravichandran sold 1,490,526 shares of Common Stock at a price per share of $19.00 in the Issuer’s underwritten follow-on offering (the “March 2015 follow-on offering”). Except for this sale in the March 2015 follow-on offering, during the past 60 days, there were no transactions in shares of Common Stock, or any securities directly or indirectly convertible into or exchangeable for shares of Common Stock, by Mr. Ravichandran, any person or entity controlled by Mr. Ravichandran or any person or entity for which Mr. Ravichandran possesses voting or investment control over the securities thereof.

(d) Not applicable.

(e) Not applicable.

There are no contracts, arrangements, understandings or relationships (legal or otherwise) among each Reporting Person and any other person or entities with respect to any securities of the Issuer, except for the following:

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SCHEDULE 13D

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SCHEDULE 13D

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SCHEDULE 13D

Signature

After reasonable inquiry and to the best of the undersigned’s knowledge and belief, the undersigned certifies that the information set forth in this statement is true, complete and correct.

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Exhibit 1.1

Endurance International Group Holdings, Inc.

Lock-Up Agreement

[date]

Credit Suisse Securities (USA) LLC

Eleven Madison Avenue

New York, NY 10010-3629

Ladies and Gentlemen:

The undersigned understands that Credit Suisse Securities (USA) LLC (“you” or the “Underwriter”) proposes to enter into an Underwriting Agreement with Endurance International Group Holdings, Inc., a Delaware corporation (the “Company”), and the Selling Stockholders named in Schedule I to such agreement, providing for a public offering of the common stock of the Company (the “Shares”) pursuant to a Registration Statement on Form S-3 to be filed with the Securities and Exchange Commission (the “SEC”) (such public offering, the “Offering”).

In consideration of the agreement by the Underwriter to offer and sell the Shares, and of other good and valuable consideration the receipt and sufficiency of which is hereby acknowledged, the undersigned agrees that, during the period specified in the following paragraph (the “Lock-Up Period”), the undersigned will not offer, sell, contract to sell, pledge, grant any option to purchase, make any short sale or otherwise dispose of any shares of common stock of the Company, or any options or warrants to purchase any shares of common stock of the Company, or any securities convertible into, exchangeable for or that represent the right to receive shares of common stock of the Company, whether now owned or hereinafter acquired, owned directly by the undersigned (including holding as a custodian) or with respect to which the undersigned has beneficial ownership within the rules and regulations of the SEC (collectively, the “Undersigned’s Shares”). The foregoing restriction is expressly agreed to preclude the undersigned from engaging in any hedging or other transaction which is designed to or which reasonably could be expected to lead to or result in a sale or disposition of the Undersigned’s Shares even if such Shares would be disposed of by someone other than the undersigned. Such prohibited hedging or other transactions would include without limitation any short sale or any purchase, sale or grant of any right (including without limitation any put or call option) with respect to any of the Undersigned’s Shares or with respect to any security that includes, relates to, or derives any significant part of its value from such Shares. If the undersigned is an officer or director of the Company, the undersigned further agrees that the foregoing provisions shall be equally applicable to any Company-directed Shares the undersigned may purchase in the Offering.

The initial Lock-Up Period will commence on the date hereof and continue for 60 days after the Offering date set forth on the final prospectus used to sell the Shares (the “Public Offering Date”) pursuant to the Underwriting Agreement.

Notwithstanding the foregoing, the foregoing restrictions shall not apply to: (i) transfers of the Undersigned’s Shares as a bona fide gift or gifts; (ii) transfers of the Undersigned’s Shares to any immediate family members of the undersigned or any trust for the direct or indirect benefit of

the undersigned or the immediate family of the undersigned, or any limited partnership the partners of which are the undersigned and/or immediate family members of the undersigned; (iii) transfers of the Undersigned’s Shares by will or intestacy; (iv) transfers of the Undersigned’s Shares to limited or general partners, members, stockholders or affiliates (as defined under Rule 12b-2 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”)) of the undersigned or, in the case of a corporation, to a wholly-owned subsidiary of the undersigned; (v) the exercise of the undersigned’s option to purchase Shares granted prior to the date hereof under a stock incentive plan or stock purchase plan of the Company described in the final prospectus used to sell the Shares, or the disposition to the Company of the Undersigned’s Shares pursuant to any contractual relationship in effect on the date of the Underwriting Agreement that provides for the disposition; (vi) transfers of the Undersigned’s Shares acquired on the open market following the Public Offering Date; (vii) the establishment of a trading plan pursuant to Rule 10b5-1 under the Exchange Act for the transfer of Shares; provided that (A) such plan does not provide for the transfer of Shares during the Lock-Up Period and (B) any public announcement regarding the establishment of such plan specifies that no transfer of Shares is permitted during the Lock-Up Period; (viii) the sale of the Undersigned’s Shares to the Underwriter in connection with the Offering; or (ix) transfers of the Undersigned’s Shares with the prior written consent of the Underwriter; provided that, in the case of any transfer or distribution pursuant to clauses (i) through (iv) above, each donee, trustee, legatee, heir, distributee, or other transferee, as the case may be, shall agree to be bound in writing by the restrictions set forth herein and such transfer or distribution shall be a disposition for no value; provided further that, in the case of any transfer, distribution, exercise or disposition pursuant to clauses (i) through (vi) above, no filing under Section 16(a) of the Exchange Act during the Lock-Up Period shall be required or shall be voluntarily made in connection therewith.

For purposes of this Lock-Up Agreement, “immediate family” shall mean any relationship by blood, marriage or adoption, not more remote than first cousin. The undersigned now has, and, except as contemplated by clauses (i) through (ix) above, for the duration of this Lock-Up Agreement will have, good and marketable title to the Undersigned’s Shares, free and clear of all liens, encumbrances, and claims whatsoever. The undersigned also agrees and consents to the entry of stop transfer instructions with the Company’s transfer agent and registrar against the transfer of the Undersigned’s Shares except in compliance with the foregoing restrictions.

In the event that during the Lock-Up Period, the Underwriter waives any prohibition on the transfer of shares of common stock of the Company held by any person or entity that beneficially owns 5% or more of the outstanding shares of common stock of the Company, the Underwriter shall be deemed to have also waived the prohibitions set forth in this Lock-Up Agreement that would otherwise have applied to the undersigned on the same terms as and with respect to the same percentage of the Undersigned’s Shares as the relative percentage of aggregate shares held by such party receiving the waiver which are subject to such waiver. In the event that, as a result of this paragraph, any of the Undersigned’s Shares are released from the restrictions imposed by this Lock-Up Agreement, the Underwriter shall use its commercially reasonable efforts to notify the undersigned within three (3) business days of the percentage of shares of Common Stock held by the undersigned that has been released; provided, that the failure to give such notice shall not give rise to any claim or liability against the Underwriter.

The undersigned understands that the Company and the Underwriter are relying upon this Lock-Up Agreement in proceeding toward consummation of the Offering. The undersigned further understands that this Lock-Up Agreement is irrevocable and shall be binding upon the undersigned’s heirs, legal representatives, successors, and assigns.

2

This Lock-Up Agreement and related restrictions shall automatically terminate and be of no further force or effect upon the earliest to occur, if any, of (a) the Underwriter, on the one hand, or the Company, on the other hand, advising the other in writing prior to the execution of the Underwriting Agreement that it has determined not to proceed with the Offering, (b) the termination of the Underwriting Agreement before the sale of any Shares to the Underwriter, (c) the registration statement filed with the SEC with respect to the Offering is withdrawn and (d) in the event that the Underwriting Agreement has not been executed by March 31, 2015, provided that the Company may by written notice to the undersigned prior to March 31, 2015 extend such date for a period of up to an additional three months.

[Signature Page Follows]

3

[Signature Page to Lock-Up Agreement]

Exhibit 99.1

Joint Filing Agreement

Each of the undersigned hereby expresses his, her or its agreement that the attached Schedule 13D (and any amendments thereto) relating to the Common Stock of Endurance International Group Holdings, Inc. is filed on behalf of each of the undersigned.