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): December 10, 2013

Gramercy Property Trust Inc.

(Exact Name of Registrant as Specified in its Charter)

(212) 297-1000

(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:

(b) Following completion of the previously announced payment by Gramercy Property Trust Inc. (the “Company”) of all accrued and unpaid dividends on its 8.125% Series A Cumulative Redeemable Preferred Stock (the “Preferred Stock”) on January 13, 2014 (the “Accrued and Unpaid Dividend Payment”), and the payment of the dividend on the Preferred Stock for the current dividend period on January 15, 2014 (the “Current Dividend Payment”, and together with the Accrued and Unpaid Dividend Payment, the “Dividend Payments”), the right of the holders of the Preferred Stock to elect one director to the Board of Directors (the “Board”) of the Company will cease, the term of office of William H. Lenehan will terminate and the number of directors constituting the Board will be reduced accordingly.

(d) On December 10, 2013, the Board approved, effective upon and subject to the completion of the Dividend Payments, the resulting termination of Mr. Lenehan’s term of office as a director and the corresponding reduction in the size of the Board, the increase of the size of the Board back to seven members and the appointment of Mr. Lenehan to fill the vacancy created by such increase, with a term expiring at the annual meeting of the Company’s common stockholders in 2014 or until his successor has been duly elected and qualified. Mr. Lenehan’s compensation for service as a director of the Company will not be changed by such appointment.

On December 10, 2013, the Board approved Articles Supplementary to the Company’s charter to reclassify 2,000,000 authorized shares of Class B-1 Non-Voting Common Stock, par value $.001 per share, and 2,000,000 authorized shares of Class B-2 Non-Voting Common Stock, par value $.001 per share, into the same number of authorized but unissued shares of common stock, par value $.001 per share, of the Company. The Articles Supplementary were filed with the Maryland State Department of Assessments and Taxation on December 10, 2013 and became effective on that date. The Articles Supplementary are attached hereto as Exhibit 3.1 and are incorporated herein by reference.

On December 11, 2013, the Company issued the press release attached hereto as Exhibit 99.1, which is incorporated herein by reference, announcing the Dividend Payments. On December 13, 2013, the Company issued the press release attached hereto as Exhibit 99.2, which is incorporated herein by reference, reporting the ex-dividend dates with respect to the Dividend Payments.

Exhibit No.

Signature

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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