8-K

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 eventreported): December 7, 2021

CLEAN ENERGY FUELS CORP.

(Exact Name of Registrant as Specified in Charter)

(949) 437-1000

(Registrant’s telephone number, includingarea 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):

Securities registered pursuant to Section 12(b) of the Act:

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.   ¨

Item 8.01. Other Events.

As previously disclosed, on March 12, 2020, the Board of Directors of Clean Energy Fuels Corp. (the “Company”) approved a share repurchase program (the “Repurchase Program”) of up to $30.0 million (exclusive of fees and commissions) of the Company’s common stock, $0.0001 par value per share (“Common Stock”). The Repurchase Program does not have an expiration date, and it may be suspended or discontinued at any time. The Company did not purchase any shares of Common Stock during the nine months ended September 30, 2021, and as of September 30, 2021, the Company had utilized $14.5 million to repurchase 7,744,386 shares of Common Stock under the Repurchase Program.

On December 7, 2021, the Company’s Board of Directors determined to resume repurchases of shares of the Company’s Common Stock pursuant to the Repurchase Program and approved an increase in the aggregate purchase amount under the Repurchase Program from $30.0 million to $50.0 million (exclusive of fees and commissions). The Repurchase Program does not obligate the Company to acquire any specific number of shares. Repurchases under the Repurchase Program may be effected from time to time through open market purchases, privately negotiated transactions, structured or derivative transactions, including accelerated share repurchase transactions, or other methods of acquiring shares, in each case subject to market conditions, applicable securities laws and other relevant factors.

Goldman Sachs & Co. has the authority to repurchase the Company’s Common Stock in the open market pursuant to a prearranged stock repurchase plan under Rule 10b5-1.

2

SIGNATURE

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

3