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): November 9, 2015

Starwood Hotels & Resorts Worldwide, Inc.

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code: (203) 964-6000

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:

Item 7.01 Regulation FD

On November 9, 2015, Starwood Hotels & Resorts Worldwide, Inc. (“Starwood”) made available additional historical and forward-looking financial information about Vistana Signature Experiences, Inc., a wholly owned subsidiary of Starwood (“Vistana”), in connection with the previously announced Reverse Morris Trust transaction entered into with, among other parties, Interval Leisure Group, Inc. (“ILG”). This additional information is attached as Exhibit 99.1 hereto.

On November 9, 2015, ILG also released its own investor presentation which includes information about Vistana, which investor presentation was solely prepared by ILG, and not Starwood.

The information in this Current Report on Form 8-K, including Exhibit 99.1 attached hereto, is furnished pursuant to Item 7.01 and shall not be deemed “filed” for any purpose and shall not be deemed incorporated by reference into any filing under the Securities Act of 1933, as amended, or the Securities Exchange Act of 1934, as amended, regardless of any general incorporation language in such filing.

Item 9.01 Financial Statements and Exhibits.

Forward-Looking Statements

This communication contains forward-looking statements within the meaning of federal securities regulations. Forward-looking statements are not guarantees of future performance and involve risks and uncertainties and other factors that may cause actual results to differ materially from those anticipated at the time the forward-looking statements are made. Further results, performance and achievements may be affected by general economic conditions including the impact of war and terrorist activity, natural disasters, business and financing conditions (including the condition of credit markets in the U.S. and internationally), foreign exchange fluctuations, cyclicality of the real estate (including residential) and the hotel and vacation ownership businesses, operating risks associated with the hotel, vacation ownership and residential businesses, relationships with associates and labor unions, customers and property owners, the impact of the internet reservation channels, our reliance on technology, domestic and international political and geopolitical conditions, competition, governmental and regulatory actions (including the impact of changes in U.S. and foreign tax laws and their interpretation), travelers’ fears of exposure to contagious diseases, risk associated with the level of our indebtedness, risk associated with potential acquisitions and dispositions and the introduction of new brand concepts and other risks and uncertainties. These risks and uncertainties are presented in detail in our filings with the Securities and Exchange Commission. There can be no assurance as to the development of future hotels in the Company’s pipeline or additional vacation ownership units. Although we believe the expectations reflected in forward-looking statements are based upon reasonable assumptions, we can give no assurance that our expectations will be attained or that results will not materially differ. We undertake no obligation to publicly update or revise any forward-looking statement, whether as a result of new information, future events or otherwise.

Additional Information 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. This communication may be deemed to be solicitation material in respect of the proposed merger between a wholly-owned subsidiary of ILG and Vistana. In connection with the proposed merger, ILG intends to file a registration statement on Form S-4, containing a proxy statement/prospectus with the Securities and Exchange Commission (“SEC”). STOCKHOLDERS OF STARWOOD AND ILG ARE URGED TO READ ALL RELEVANT DOCUMENTS FILED WITH THE SEC, INCLUDING THE PROXY STATEMENT/PROSPECTUS, BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION ABOUT

THE PROPOSED MERGER. Investors and security holders will be able to obtain copies of the proxy statement/prospectus as well as other filings containing information about ILG, Starwood and Vistana, without charge, at the SEC’s website, http://www.sec.gov. Copies of documents filed with the SEC by ILG will be made available free of charge on ILG’s investor relations website. Copies of documents filed with the SEC by Starwood will be made available free of charge on Starwood’s investor relations website.

Participants in Solicitation

Starwood and its directors and executive officers, and ILG and its directors and executive officers, may be deemed to be participants in the solicitation of proxies from the holders of ILG common stock in respect of ILG’s stock issuance in connection with the proposed merger. Information about the directors and executive officers of Starwood is set forth in the proxy statement for Starwood’s 2015 Annual Meeting of Stockholders, which was filed with the SEC on April 17, 2015. Information about the directors and executive officers of ILG is set forth in the proxy statement for ILG’s 2015 Annual Meeting of Stockholders, which was filed with the SEC on April 6, 2015. Investors may obtain additional information regarding the interest of such participants by reading the proxy statement/prospectus regarding the proposed merger when it becomes available.

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.

Date: November 9, 2015

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