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 31, 2012 (October 30, 2012)

AMERICAN REALTY CAPITAL TRUST, INC.

(Exact name of Registrant as specified in its charter)

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:

¨  Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

x  Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

¨  Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

¨  Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Item 8.01. Other Events.

On October 30, 2012, American Realty Capital Trust, Inc. (the “Company”) hosted its third quarter conference call and webcast. In addition, the Company issued a letter to stockholders with respect to its financial results for the three and nine months ended September 30, 2012. The stockholder letter and the conference call included a discussion regarding the Company’s entry into an Agreement and Plan of Merger (the “Merger Agreement”) with Realty Income Corporation, a Maryland corporation (“Realty”), and Tau Acquisition LLC, a Delaware limited liability company and wholly owned subsidiary of Realty.

Copies of the stockholder letter and the transcript of the earnings conference call are attached as Exhibit 99.1 and 99.2, respectively, to this Current Report on Form 8-K.

Additional Information about the Proposed Merger and Where to Find It

This communication does not constitute an offer to sell or the solicitation of an offer to buy any securities or a solicitation of any vote or approval. In connection with the proposed merger, the Company and Realty have filed a preliminary joint proxy statement and Realty has filed with the Securities and Exchange Commission (the “SEC”) a registration statement on Form S-4 containing a preliminary joint proxy statement/prospectus and other documents with respect to Realty’s proposed acquisition of the Company. INVESTORS ARE URGED TO READ THE JOINT PROXY STATEMENT/PROSPECTUS (INCLUDING ALL AMENDMENTS AND SUPPLEMENTS THERETO) AND OTHER RELEVANT DOCUMENTS FILED BY REALTY WITH THE SEC IF AND WHEN THEY BECOME AVAILABLE BECAUSE THEY CONTAIN IMPORTANT INFORMATION ABOUT THE PROPOSED MERGER.

Investors may obtain free copies of the registration statement, the joint proxy statement/prospectus and other relevant documents filed by the Company and Realty, as applicable, with the SEC (if and when they become available) through the website maintained by the SEC at www.sec.gov. Copies of the documents filed by the Company with the SEC are also available free of charge on the Company’s website at http://ir.arctreit.com, and copies of the documents filed by Realty with the SEC are available free of charge on Realty’s website at http://www.realtyincome.com.

The Company, Realty and their respective directors and executive officers may be deemed to be participants in the solicitation of proxies from the Company’s and Realty’s stockholders in respect of the proposed merger. Information regarding the Company’s directors and executive officers can be found in the Company’s definitive proxy statement filed with the SEC on May 21, 2012. Information regarding Realty’s directors and executive officers can be found in Realty’s definitive proxy statement filed with the SEC on March 30, 2012. Additional information regarding the interests of such potential participants will be included in the joint proxy statement/prospectus and other relevant documents filed with the SEC in connection with the proposed merger if and when they become available. These documents are available free of charge on the SEC’s website and from the Company or Realty, as applicable, using the sources indicated above.

Forward-Looking Statements

Information set forth in this Schedule 14A (including information included or incorporated by reference herein) contains “forward-looking statements” (as defined in Section 21E of the Securities Exchange Act of 1934, as amended), which reflect the Company’s and Realty’s expectations regarding future events. The forward-looking statements involve a number of risks, uncertainties and other factors that could cause actual results to differ materially from those contained in the forward-looking statements. Such forward-looking statements include, but are not limited to whether and when the transactions contemplated by the Merger Agreement will be consummated, the new combined company’s plans, market and other expectations, objectives, intentions and other statements that are not historical facts.

The following additional factors, among others, could cause actual results to differ from those set forth in the forward-looking statements: the ability to obtain regulatory approvals for the transaction and the approval of the Merger Agreement by the stockholders of both parties; unexpected costs or unexpected liabilities that may arise from the transaction, whether or not consummated; the inability to retain key personnel; continuation or deterioration of current market conditions; future regulatory or legislative actions that could adversely affect the companies; and the business plans of the customers of the respective parties. Additional factors that may affect future results are contained in the Company’s and Realty’s filings with the SEC, which are available at the SEC’s website at www.sec.gov. The Company and Realty disclaim any obligation to update and revise statements contained in these materials based on new information or otherwise.

Item 9.01.        Financial Statements and Exhibits

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.