UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 10-Q/A

(Amendment No. 1)

For the quarterly period ended June 30, 2011

Or

For the transition period from            to

Commission file number 000-28018

Yahoo! Inc.

(Exact name of Registrant as specified in its charter)

701 First Avenue

Sunnyvale, California 94089

(Address of principal executive offices, including zip code)

Registrant’s telephone number, including area code: (408) 349-3300

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  x    No  ¨

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted 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 and post such files).    Yes  x    No  ¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See the definitions of “large accelerated filer,” “accelerated filer,” and “smaller reporting company” in Rule 12b-2 of the Exchange Act.

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).    Yes  ¨    No  x

Indicate the number of shares outstanding of each of the issuer’s classes of common stock, as of the latest practicable date.

EXPLANATORY NOTE

This Amendment No. 1 to Form 10-Q (this “Amendment”) amends the Quarterly Report on Form 10-Q for the quarter ended June 30, 2011, originally filed on August 8, 2011 (the “Original 10-Q”), of Yahoo! Inc., a Delaware corporation (“Yahoo!” or the “Company”). The Company is filing this Amendment to amend Part II, Item 6 of the Original 10-Q to include revised versions of (i) Exhibit 10.18(H), Fourth Amendment to Search and Advertising Services and Sales Agency Agreement, dated as of December 13, 2010, by and between Yahoo! and Microsoft Corporation, and (ii) Exhibit 10.18(I), Fifth Amendment to Search and Advertising Services and Sales Agency Agreement, dated as of July 2, 2011, by and between Yahoo! and Microsoft Corporation.

This Amendment should be read in conjunction with the Original 10-Q and the Company’s other filings made with the Securities and Exchange Commission subsequent to the filing of the Original 10-Q on August 8, 2011. The Original 10-Q has not been amended or updated to reflect events occurring after August 8, 2011, except as specifically set forth in this Amendment.

Item 6. Exhibits

The exhibits listed in the Index to Exhibits (following the signatures page of this Report) are filed with, or incorporated by reference in, this Report.

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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 thereunto duly authorized.

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YAHOO! INC.

Index to Exhibits

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