UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-Q/A

(Amendment No. 1)

(Mark One)

For the quarterly period ended September 30, 2011

or

For the transition period from              to             

Commission File Number: 001-16073

OPENWAVE SYSTEMS INC.

(Exact name of registrant as specified in its charter)

(650) 480-8000

(Registrant’s telephone number, including area code)

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

As of October 31, 2011 there were 85,778,318 shares of the registrant’s Common Stock outstanding.

OPENWAVE SYSTEMS INC.

Table of Contents

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Explanatory Note

The purpose of this amendment on Form 10-Q/A to the Quarterly Report on Form 10-Q of Openwave Systems Inc. for the quarterly period ended September 30, 2011 is to furnish Exhibit 101 to the Form 10-Q within the 30-day grace period provided for the initial submission of interactive data files in accordance with Rule 405(a)(2) of Regulation S-T.

This amendment on Form 10-Q/A does not change any other items in the Form 10-Q as originally filed, nor does this amendment on Form 10-Q/A reflect subsequent events occurring after the original filing date of the Form 10-Q.

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Item 6. EXHIBITS

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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.

Date: November 8, 2011

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