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): April 5, 2013

Cole Credit Property Trust III, Inc.

(Exact Name of Registrant as Specified in Its Charter)

2325 East Camelback Road, Suite 1100, Phoenix, Arizona 85016

(Address of principal executive offices) (Zip Code)

(602) 778-8700

(Registrant’s telephone number, including area code)

None

(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:

On April 5, 2013, Cole Credit Property Trust III, Inc., a Maryland corporation (the “Company”), issued a press release announcing that the special committee of the board comprised exclusively of independent directors has rejected the unsolicited proposals, dated March 27, 2013 and April 2, 2013, from American Realty Capital Properties, Inc. (“ARCP”) to acquire 100% of the outstanding common stock of the Company. A copy of the press release is filed as Exhibit 99.1 to this Current Report on Form 8-K and is incorporated herein by reference solely for purposes of this Item 7.01 disclosure. A copy of a presentation describing the Special Committee’s rationale for rejecting the unsolicited proposals from ARCP is attached as Exhibit 99.2 to this Current Report on Form 8-K and is incorporated by reference herein.

Pursuant to the rules and regulations of the Securities and Exchange Commission, the information in this Item 7.01 disclosure, including Exhibit 99.1 and Exhibit 99.2 and the information set forth therein, is deemed to have been furnished to, and shall not be deemed to be “filed” with, the Securities and Exchange Commission (the “SEC”).

The information provided in Item 7.01 is hereby incorporated by reference into this Item 8.01.

Additional Information and Where to Find It

This Current Report on Form 8-K and the exhibits attached hereto may be deemed to be solicitation material in respect of the charter amendments to be presented to the Company’s stockholders for consideration at the 2013 annual stockholders’ meeting. The Company has filed a preliminary proxy statement and expects to file a definitive proxy statement with the SEC in connection with the 2013 annual stockholders’ meeting. STOCKHOLDERS ARE URGED TO READ THE DEFINITIVE PROXY STATEMENT AND ANY OTHER RELEVANT DOCUMENTS FILED WITH THE SEC WHEN THEY BECOME AVAILABLE, BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION. Stockholders may obtain a free copy of the definitive proxy statement and other relevant documents filed with the SEC at the SEC’s website at www.sec.gov. Copies of the documents filed by the Company with the SEC will be available free of charge by directing a written request to Cole Credit Property Trust III, Inc., 2325 East Camelback Road, Suite 1100, Phoenix, Arizona 85016, Attention: Investor Relations.

Participants in Solicitation

The Company and its directors and executive officers and other members of management may be deemed to be participants in the solicitation of proxies in respect of the charter amendments to be considered at the 2013 annual stockholders’ meeting of the Company. Information regarding the interests of the Company’s directors and executive officers in the proxy solicitation will be included in the Company’s definitive proxy statement.

Forward-Looking Statements

In addition to historical information, this Current Report on Form 8-K and the exhibits attached hereto contain forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended (the “Securities Act”), and Section 21E of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), including statements regarding the Company’s transaction with Cole Holdings Corporation and the ability to consummate the transaction. The Company intends for all such forward-looking statements to be covered by the safe harbor provisions for forward-looking statements contained in Section 27A of the Securities Act and Section 21E of the Exchange Act, as applicable. Such statements include, in particular, statements about the Company’s plans, strategies, and prospects and are subject to certain risks and uncertainties, as well as known and unknown risks, which could cause actual results to differ materially from those projected or anticipated. Therefore, such statements are not intended to be a guarantee of the Company’s performance in future periods. Such forward-looking statements can generally be identified by the use of forward-looking terminology such as “may,” “will,” “would,” “could,” “should,” “expect,” “intend,” “anticipate,” “estimate,” “believe,” “continue,” or other similar words. Readers are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the

date of this Current Report on Form 8-K and the exhibit attached hereto. The Company makes no representation or warranty (express or implied) about the accuracy of any such forward-looking statements contained in this Current Report on Form 8-K or the exhibit attached hereto, and does not intend, and undertakes no obligation, to publicly update or revise any forward-looking statements, whether as a result of new information, future events, or otherwise.

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.

Exhibit Index