Red Robin Gourmet Burgers (RRGB)

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, DC 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): August 25, 2005

RED ROBIN GOURMET BURGERS, INC.

Registrant’s telephone number, including area code: (303) 846-6000

Not Applicable

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:

Red Robin Gourmet Burgers, Inc. (the “Company”) and Dennis B. Mullen have entered into a non-qualified stock option agreement in conjunction with Mr. Mullen’s appointment as chairman of the board of directors and chief executive officer of the Company. Effective as of August 25, 2005, Mr. Mullen was awarded an option to purchase 100,000 shares of the Company’s common stock at a strike price of $45.79 per share, the price of the Company’s common stock as of the close of The NASDAQ National Market on such date. The option has a stated term of 10 years, and vests ratably in substantially equal monthly installments over a two year period beginning September 25, 2005. Except in any instance in which Mr. Mullen terminates his employment voluntarily or in which Mr. Mullen’s employment is terminated for “cause” (as defined in the stock option agreement), the vested portion of the option will remain exercisable for a period of two years following the date upon which Mr. Mullen ceases to be a director, officer or employee of the Company.

A copy of the non-qualified stock option agreement is filed with this report as Exhibit 10.1 and is incorporated herein by reference.

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