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): May 22, 2013

SunPower Corporation

(Exact name of registrant as specified in its charter)

001-34166

(Commission

File Number)

77 Rio Robles, San Jose, California 95134

(Address of principal executive offices, with zip code)

(408) 240-5500

(Registrant’s telephone number, including area code)

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 (see General Instruction A.2. below):

On May 22, 2013, SunPower Corporation (“SunPower”) issued a press release announcing that it intends to offer, subject to market and other conditions, $300 million in aggregate principal amount of senior convertible debentures (the “Debentures”). The Debentures will mature in June 2018 and will be convertible into shares of SunPower’s common stock, par value $0.001 per share. The Debentures will be offered and sold in a private offering made in reliance upon exemptions from the registration requirements of the Securities Act of 1933 (the “Securities Act”). $100 million in aggregate principal amount of the Debentures will be offered to qualified institutional buyers pursuant to Rule 144A under the Securities Act, and the remaining $200 million in aggregate principal amount of the Debentures will be offered to Total Gas & Power USA, SAS, a subsidiary of Total S.A. which owns approximately 65% of SunPower’s outstanding common stock and which is an institutional accredited investor pursuant to Regulation D under the Securities Act. The full text of the press release is being furnished as Exhibit 99.1 to this report.

In accordance with General Instruction B.2 of Form 8-K, the information set forth in Item 7.01 of this report and in the press release is deemed to be “furnished” and shall not be deemed to be “filed” for purposes of the Securities Exchange Act of 1934, as amended. The information set forth in Item 7.01 of this report shall not be deemed an admission as to the materiality of any information in this report on Form 8-K that is required to be disclosed solely to satisfy the requirements of Regulation FD.

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.

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