UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

Current Report

Pursuant to Section 13 or 15(d)

of The Securities Exchange Act of 1934

Date of Report (Date of Earliest Event Reported):

December 8, 2017

MATTEL, INC.

(Exact name of registrant as specified in its charter)

(310) 252-2000

Registrant’s telephone number, including area code

N/A

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Section 5 - Corporate Governance and Management

Mattel, Inc. (the “Company”) has elected to change the trustee for the Mattel, Inc. Personal Investment Plan (the “Plan”). As a result of this change, there will be a blackout period in which Plan participants and beneficiaries temporarily will be unable to (i) direct or diversify investments in their individual accounts or (2) obtain a distribution from the Plan. The blackout period will begin on December 29, 2017 and end no later than January 5, 2018 (the “Blackout Period”).

On December 8, 2017, the Company sent a notice of the Blackout Period (the “Blackout Period Notice”) to the members of its Board of Directors and executive officers pursuant to Section 306 of the Sarbanes-Oxley Act of 2002 and Rule 104 of Regulation BTR of the Securities Exchange Act of 1934, informing them that they would be prohibited during the Blackout Period from purchasing and selling shares of the Company’s common stock (including derivative securities pertaining to such shares) they acquire or have previously acquired in connection with their service or employment as a director or executive officer of the Company.

A copy of the Blackout Period Notice is attached hereto as Exhibit 99.1 and is incorporated herein by reference. During the Blackout Period and for a period of two years after the ending date of the Blackout Period, security holders or other interested persons may obtain, without charge, information about the actual beginning and ending dates of the Blackout Period and other information regarding the Blackout Period by contacting Bill Whitman, Director Global Benefits, by telephone at (310) 252-3156, or in writing, at 333 Continental Boulevard, El Segundo, California 90245.

Section 9 - Financial Statements and Exhibits

(d) Exhibits:

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.