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): October 4, 2013

Marin Software Incorporated

(Exact name of registrant as specified in its charter)

(415) 399-2580

(Registrant’s telephone number, including area code)

(Former name or former address, if changed since last report)

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:

Item 5.02(d) Election of a New Director.

On October 4, 2013, upon the recommendation of the Nomination and Corporate Governance Committee, the Board of Directors (the “Board”) of Marin Software Incorporated (the “Company”) approved the appointments of James Barrese and Allan Leinwand as directors of the Company, with immediate effect. In connection with the appointment to the Board, each of Messrs. Barrese and Leinwand will enter into the Company’s standard indemnification agreement for directors.

In connection with the appointment, the Board approved expanding the size of the Board to seven directors. Mr. Barrese and Mr. Leinwand were appointed as Class III Directors of the Company, along with Chris Lien. Mr. Barrese and Mr. Leinwand shall hold office for a term expiring at the 2016 Annual Meeting of the Company’s stockholders, which is the next stockholder meeting at which Class III Directors will be elected.

Upon the effective date of their appointment to the Board, Mr. Barrese and Mr. Leinwand were each granted an option to purchase 30,000 shares of common stock of the Company pursuant to the Company’s 2013 Equity Incentive Plan. The exercise price of each option was $11.81 per share, the closing price of the Company’s common stock on the date of grant. The shares vest ratably over three years, with one-third of the shares vesting on each yearly anniversary of the date of grant. Any unvested shares will accelerate upon a change of control of the Company.

At the time of the appointment, it was not determined whether Mr. Barrese and Mr. Leinwand would sit on any committees of the Board.

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.