13D Filing: Marcato Capital Management and Deckers Outdoor Corp (DECK)

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, DC 20549

SCHEDULE 13D

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 6)*

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

December 4, 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).

SCHEDULE 13D

SCHEDULE 13D

SCHEDULE 13D

SCHEDULE 13D

SCHEDULE 13D

SCHEDULE 13D

This amendment No. 6 to Schedule 13D (this Amendment No. 6), 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. 6, 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. 6 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. Purpose of Transaction

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

On December 4, 2017, Marcato International submitted to the Issuer an update and supplement to the Notice to notify the Issuer of Marcato
Internationals withdrawal of Deborah M. Derby, Matthew P. Hepler, Robert D. Huth, Jan Rogers Kniffen, Mitchell A. Kosh and Nathaniel J. Lipman as Nominees. A copy of such update and supplement is filed herewith as Exhibit L and is incorporated
herein by reference. Kirsten J. Feldman, Steve Fuller and Anne Waterman continue to be Marcatos Nominees for election to the Board at the 2017 Annual Meeting and Marcato intends to nominate each of Kirsten J. Feldman, Steve Fuller and Anne
Waterman at the 2017 Annual Meeting.

SCHEDULE 13D

Item 5. Interest in Securities of the Issuer

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 8.5% 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 31,961,417 Shares outstanding as of
November 3, 2017 (based on disclosure in the Issuers quarterly report on Form 10-Q filed with the SEC on November 9, 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. McGuires 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 are 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.

SCHEDULE 13D

Item 7. Material to be Filed as Exhibits

Exhibit A: Joint Filing Agreement*

Exhibit B: Schedule
of Transactions in Shares*

Exhibit C: Press Release, dated June 27, 2017*

Exhibit D: Schedule of Transactions in Shares*

Exhibit E:
Notice, dated September 13, 2017*

Exhibit F: Press Release, dated September 13, 2017*

Exhibit G: Form of Engagement and Indemnification Agreement*

Exhibit H: Schedule of Transactions in Shares*

Exhibit I:
Complaint, filed in the Court of Chancery of the State of Delaware, dated October 23, 2017*

Exhibit J: Update and Supplement to the Notice, dated
October 31, 2017*

Exhibit K: Schedule of Transactions in Shares*

Exhibit L: Second Update and Supplement to the Notice, dated December 4, 2017

SCHEDULE 13D

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: December 4, 2017