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): March 9, 2015

Columbia Property Trust, Inc.

(Exact name of registrant as specified in its charter)

Commission File Number: 000-51262

One Glenlake Parkway, Suite 1200

Atlanta, GA 30328

(Address of principal executive offices, including zip code)

(404) 465-2200

(Registrant’s telephone number, including area code)

Not Applicable

(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 (see General Instruction A.2. below):

On March 9, 2015, Columbia Property Trust Operating Partnership, L.P. (the “Operating Partnership”), the operating partnership and wholly-owned subsidiary of Columbia Property Trust, Inc. (the “Company”), issued $350.0 million in aggregate principal amount of 4.150% Senior Notes due 2025 (the “Notes”), which mature on April 1, 2025, pursuant to an indenture, dated as of March 12, 2015 (the “Base Indenture” as amended and supplemented by a supplemental indenture (the “Supplemental Indenture”), dated March 12, 2015, the “Indenture”), by and among the Operating Partnership, the Company and U.S. Bank National Association, as trustee. The Notes are fully and unconditionally guaranteed by the Company.

Copies of the Base Indenture and the Supplemental Indenture are attached hereto as Exhibits 4.1 and 4.2 and are incorporated herein by reference. The foregoing summaries of the Base Indenture and the Supplemental Indenture do not purport to be complete and are qualified in their entirety by reference to the Base Indenture and Supplemental Indenture.

On March 9, 2015, the Operating Partnership and the Company entered into an agreement (the “Underwriting Agreement”) with J.P. Morgan Securities LLC, Morgan Stanley & Co. LLC and Wells Fargo Securities, LLC, as representatives of the underwriters listed on Schedule 1 thereto (the “Underwriters”). Pursuant to the Underwriting Agreement, the Operating Partnership agreed to sell and the Underwriters agreed to purchase from the Operating Partnership, subject to and upon the terms and conditions set forth in the Underwriting Agreement, the Notes.

A copy of the Underwriting Agreement is attached hereto as Exhibit 1.1 and is incorporated herein by reference. The foregoing summary does not purport to be complete and is qualified in its entirety by reference to the Underwriting Agreement.

The Company is filing this Current Report on Form 8-K so as to file with the Securities and Exchange Commission certain items that are to be incorporated by reference into its Registration Statement on Form S-3ASR (Registration No. 333-198764).

On March 9, 2015, the Company issued a press release announcing the pricing of the offering of the Notes. A copy of this press release is attached hereto as Exhibit 99.1 and is incorporated herein by reference.

(d) Exhibits.

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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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