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( Mark One ) UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington , D.C. 20549 FORM 10 - K ANNUAL REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31 , 2020 TRANSITION REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Delaware ( State or other jurisdiction of incorporation or organization ) Large accelerated filer Non - accelerated filer or Title of each class Common stock , $ 1.00 per share Commission File Number 001-05647 MATTEL , INC . ( Exact name of registrant as specified in its charter ) ý 333 Continental Blvd. El Segundo , CA 90245-5012 ( Address of principal executive offices ) Registrant's telephone number , including area code ( 310 ) 252-2000 Securities registered pursuant to Section 12 ( b ) of the Act : Trading Symbol ( s ) . MAT 95-1567322 Securities registered pursuant NONE ( I.R.S. Employer Identification No. ) Name of each exchange on which registered The Nasdaq Global Select Market No No ý Indicate by check mark if the registrant is a well - known seasoned issuer , as defined in Rule 405 of the Securities Act . Yes ý Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15 ( d ) of the Act . Yes Indicate by check mark whether the registrant ( 1 ) has filed all reports required to be filed by Section 13 or 15 ( d ) of the Securities Exchange Act of 1934 during the preceding 12 months ( or for such shorter period that the registrant was required to file such reports ) , and ( 2 ) has been subject to such filing requirements for the past 90 days . Yes ý No Section 12 ( g ) of the Act : Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S T ( §232.405 of this chapter ) during the preceding 12 months ( or for such shorter period that the registrant was required to submit such files ) . Yes ý No Indicate by check mark whether the registrant is a large accelerated filer , an accelerated filer , a non - accelerated filer , a smaller reporting company , or an emerging growth company . See the definitions of “ large accelerated filer , ” “ accelerated filer , ” “ smaller reporting company , ” and “ emerging growth company " in Rule 12b - 2 of the Exchange Act . Accelerated filer Smaller reporting company 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 . 0 0 Indicate by check mark whether the registrant has filed a report on and attestation to its management's assessment of the effectiveness of its internal control over financial reporting under Section 404 ( b ) of the Sarbanes - Oxley Act ( 15 U.S.C. 7262 ( b ) ) by the registered public accounting firm that prepared or issued its audit report . ý Indicate by check mark whether the registrant is a shell company ( as defined in Rule 12b - 2 of the Act ) . Yes No The aggregate market value of the voting and non - voting common equity held by non - affiliates of the registrant was $ 3,355,214,231 based upon the closing market price as of the close of business June 30 , 2020 , the last business day of the registrant's most recently completed second fiscal quarter . Number of shares outstanding of registrant's common stock , $ 1.00 par value , as of February 8 , 2021 : 348,169,738 shares DOCUMENTS INCORPORATED BY REFERENCE Portions of the Mattel , Inc. 2021 Proxy Statement , filed with the Securities and Exchange Commission ( " SEC " ) within 120 days after the closing of the registrant's fiscal year ( incorporated into Part III to the extent stated herein ) .