UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, DC 20549

SCHEDULE 13D

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 5)*

Deckers Outdoor Corporation

(Name of Issuer)

Common Stock, $0.01 par value

(Title of Class of Securities)

243537107

(CUSIP Number)

Richard T. McGuire III

Marcato Capital Management LP

Four Embarcadero Center, Suite 2100

San Francisco, CA 94111

(415) 796-6350

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

Copies to:

Richard M. Brand

Joshua A. Apfelroth

Cadwalader, Wickersham & Taft LLP

One World Financial Center

New York, NY 10281

(212) 504-6000

October 31, 2017

(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 which is the subject of this Schedule 13D, and is filing this schedule because of Rule 13d-1(e), 13d-1(f) or 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 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).

This amendment No. 5 to Schedule 13D (this “Amendment No. 5”), amends and supplements the Schedule 13D filed on February 8, 2017 (the “Initial 13D” and, as amended and supplemented through the date of this Amendment No. 5, collectively, the “Schedule 13D”) by the Reporting Persons, relating to the common stock, par value $0.01 per share (the “Shares”), of Deckers Outdoor Corporation, a Delaware corporation (the “Issuer”). Capitalized terms not defined in this Amendment No. 5 shall have the meaning ascribed to them in the Schedule 13D.

The information set forth in response to each separate Item below shall be deemed to be a response to all Items where such information is relevant.

Item 4 of the Schedule 13D is hereby supplementally amended as follows:

On October 24, 2017, the Issuer announced the resignation of Angel Martinez from the Board and amended and restated the Bylaws to decrease the authorized number of directors on the Board from ten (10) to nine (9). The Issuer further announced that the Board fixed the size of the Board at nine (9) directors, which represents a reduction from the previous ten (10) director Board. In light of these changes, Marcato has elected to reduce the size of its slate from ten (10) nominees to nine (9) nominees. Accordingly, on October 31, 2017, Marcato International submitted to the Issuer an update and supplement to the Notice to notify the Issuer of Marcato International’s withdrawal of Michael W. Rayden as a Nominee. A copy of such update and supplement is filed herewith as Exhibit J and is incorporated herein by reference.

Item 5 of the Schedule 13D is hereby amended and restated in its entirety to read as follows:

(a) As of the date hereof, (i) Marcato and Mr. McGuire may each be deemed to be the beneficial owner of 2,702,531 Shares (the “Marcato Shares”), constituting approximately 8.4% of the outstanding Shares, (ii) Marcato International may be deemed to be the beneficial owner of 2,556,294 Shares, constituting approximately 8.0% of the outstanding Shares and (iii) Marcato Encore LLC and Marcato Encore Fund may each be deemed to be the beneficial owner of 146,237 Shares, constituting approximately 0.5% of the outstanding Shares, each based upon a total of 32,036,625 Shares outstanding as of September 15, 2017 (based on disclosure in the Issuer’s preliminary proxy statement on Schedule 14A filed with the SEC on October 31, 2017).

(b) Marcato International may be deemed to have the shared power to vote or direct the vote (and the shared power to dispose or direct the disposition) of 2,556,294 Shares. Marcato Encore Fund may be deemed to have the shared power to vote or direct the vote (and the shared power to dispose or direct the disposition) of 146,237 Shares. Marcato, as the investment manager of Marcato International and the sole member of Marcato Encore LLC, which is the investment manager of Marcato Encore Fund, may be deemed to have the shared power to vote or direct the vote (and the shared power to dispose or direct the disposition) of the Marcato Shares and, therefore, Marcato may be deemed to be the beneficial owner of the Marcato Shares. Marcato Encore LLC, as the investment manager of Marcato Encore Fund, may be deemed to have the shared power to vote or direct the vote (and the shared power to dispose or direct the disposition) of 146,237 Shares and, therefore, Marcato may be deemed to be the beneficial owner of the such shares. By virtue of Mr. McGuire’s position as the managing partner of Marcato, Mr. McGuire may be deemed to have the shared power to vote or direct the vote (and the shared power to dispose or direct the disposition) of the Marcato Shares and, therefore, Mr. McGuire may be deemed to be the beneficial owner of the Marcato Shares.

(c) The transactions by the Reporting Persons in the securities of the Issuer during the past sixty days are set forth in Exhibit H and K, which is incorporated herein by reference. Except as set forth in Exhibit H and K, there have been no other transactions by the Reporting Persons in the securities of the Issuer in the past sixty days.

(d) The limited partners of (or investors in) Marcato International, or their respective subsidiaries or affiliated entities, for which Marcato or its affiliates acts as general partner and/or investment manager have the right to participate in the receipt of dividends from, or proceeds from the sale of, the Shares held for the accounts of their respective funds in accordance with their respective limited partnership interests (or investment percentages) in their respective funds. The limited partners of (or investors in) Marcato Encore Fund, or their respective subsidiaries or affiliated entities, for which Marcato Encore LLC or its affiliates acts as general partner and/or investment manager have the right to participate in the receipt of dividends from, or proceeds from the sale of, the Shares held for the accounts of their respective funds in accordance with their respective limited partnership interests (or investment percentages) in their respective funds.

Item 6 of the Schedule 13D is hereby supplementally amended as follows:

On October 26, 2017, Marcato International sold American-style call options referencing an aggregate of 750,000 Shares, each with a strike price of $80, which are exercisable through January 19, 2018.

Except for the arrangements described herein, to the best knowledge of the Reporting Persons, there are no other contracts, arrangements, understandings or relationships (legal or otherwise) among the persons named in Item 2 of the Schedule 13D and between such persons and any other person with respect to any securities of the Issuer, including but not limited to, transfer or voting of any of the securities, finder’s fees, joint ventures, loan or option arrangements, puts or calls, guarantees of profits, division of profit or loss, or the giving or withholding of proxies.

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

Dated: October 31, 2017

EXHIBIT J

Marcato International Master Fund, Ltd.

c/o Marcato Capital Management LP

Four Embarcadero Center

Suite 2100

San Francisco, CA 94111

October 31, 2017

Deckers Outdoor Corporation

250 Coromar Drive

Goleta, CA 93117

Dear Corporate Secretary:

Reference is made to the Notice of Stockholder Proposal and Nomination of Candidates for Election to the Board of Directors, dated September 13, 2017 (the “Notice”), pursuant to which Marcato International Master Fund, Ltd. (“Stockholder”) notified Deckers Outdoor Corporation, a Delaware corporation (the “Corporation”) of Stockholder’s decision (i) to propose the repeal of each provision of, or amendment to, the Amended and Restated Bylaws of the Corporation (the “Bylaws”) adopted by the board of directors of the Corporation (the “Board”) subsequent to May 24, 2016 without the approval of the stockholders of the Corporation and (ii) to propose the nomination of and nominate candidates for election to the Board (the “Nomination Proposal”), in each case, at the 2017 annual meeting of stockholders of the Corporation (including any adjournments or postponements thereof or any special meeting that may be called in lieu thereof, the “2017 Annual Meeting”). Capitalized terms used but not defined herein shall have the meaning ascribed to such terms in the Notice.

As you are aware, on October 24, 2017, the Corporation announced the resignation of Angel Martinez from the Board and amended and restated the Bylaws to decrease the authorized number of directors on the Board from ten (10) to nine (9). The Corporation further announced that the Board fixed the size of the Board at nine (9) directors, which represents a reduction from the previous ten (10) director Board. In light of these changes, Marcato has elected to reduce the size of its slate from ten (10) nominees to nine (9) nominees. Accordingly, Stockholder hereby delivers this update and supplement to the Notice (this “Update and Supplement”) to notify the Corporation of Stockholder’s withdrawal of Michael W. Rayden as a Nominee.

*    *    *

Stockholder reserves the right to further nominate, substitute or add additional persons, including Michael W. Rayden, in the event that (a) the Corporation purports to increase the number of directorships, (b) the Corporation makes or announces any changes to the Bylaws or takes or announces any other action that purports to have, or if consummated would purport to have, the effect of disqualifying any of the Nominees or any additional nominee nominated pursuant to the foregoing and/or (c) any Nominee is unable or hereafter becomes unwilling for any reason to serve as a director on the Board. Additional nominations made pursuant to the preceding clauses (a) and/or (b) are without prejudice to the position of Stockholder that any further attempt to change the size of the Board or disqualify any of the Nominees through Bylaw amendments or otherwise would constitute unlawful manipulation of the Corporation’s corporate machinery. Stockholder further reserves the right to (a) withdraw any or all of the Nominees and/or (b) nominate fewer than all of the Nominees listed herein and/or re-designate one or more of such individuals as alternate nominees.

Please be advised that the delivery of this Update and Supplement and the Marcato Parties’ compliance with the Bylaws and with applicable law in respect thereof do not constitute an admission by the Marcato Parties as to the legality, validity or enforceability of any particular requirement or provision of the Bylaws, and the Marcato Parties reserve the right to contest or challenge the legality, validity or enforceability thereof in any and all respects. The delivery of any additional information provided by or on behalf of the Marcato Parties to the Corporation from and after the date hereof, whether at the request of the Corporation or otherwise, shall not be deemed to constitute an admission by the Marcato Parties that this Update and Supplement is in any way defective or that any such information was required to be delivered to the Corporation pursuant to the Bylaws or applicable law.

Please direct any questions regarding the information contained in this Update and Supplement to Richard M. Brand, Esq., Cadwalader, Wickersham & Taft LLP, 200 Liberty Street, New York, New York 10281, (212) 504-5757 (Phone), (212) 504-6666 (Facsimile) or Jason M. Halper, Esq., Cadwalader, Wickersham & Taft LLP, 200 Liberty Street, New York, New York 10281, (212) 504-6300 (Phone), (212) 504-6666 (Facsimile).

[Remainder of Page Intentionally Left Blank]

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IN WITNESS WHEREOF, the undersigned has caused this Update and Supplement to be duly executed on the date first above written.

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EXHIBIT K

Schedule of Transactions in Shares

The following table sets forth all transactions with respect to Shares effected in the last sixty days by the Reporting Persons or on behalf of the Reporting Persons in respect of the Shares, inclusive of any transactions effected through 4:00 p.m., New York City time, on October 30, 2017. All such transactions were sales effected in the open market.

Marcato International Master Fund Ltd.