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 24, 2015

Kraft Foods Group, Inc.

Exact Name of Registrant as specified in its Charter

Commission File Number 001-35491

Three Lakes Drive, Northfield, IL 60093-2753

(Address of principal executive Offices, including zip code)

Telephone: (847) 646-2000

(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:

On March 24, 2015, the Board of Directors (the “Board”) of Kraft Foods Group, Inc. (the “Company” or “Kraft”) amended the Company’s Amended and Restated By-laws (the “By-laws”) by adding a new Article XIII (the “Amendment”), which provides that unless the Company consents in writing to the selection of an alternative forum, to the greatest extent permitted by applicable law, the sole and exclusive forum for (i) any derivative action or proceeding brought on behalf of the Company, (ii) any action asserting a claim of breach of a legal or fiduciary duty owed by any director or officer or other employee of the Company to the Company or the Company’s shareholders, (iii) any action asserting a claim against the Company or any director or officer or other employee of the Company arising pursuant to any provision of the Virginia Stock Corporation Act or the Amended and Restated Articles of Incorporation of the Company or the By-laws (in each case, as they may be amended from time to time), or (iv) any action asserting a claim against the Company or any director or officer or other employee of the Company governed by the internal affairs doctrine, shall be the Circuit Court of the County of Henrico in the Commonwealth of Virginia or the United States District Court for the Eastern District of Virginia, Richmond Division.

The By-laws, as amended, are filed as Exhibit 3.1 to this report and are incorporated by reference herein. The foregoing summary of the Amendment is qualified in its entirety by reference to the full text of the By-laws, as amended.

On March 25, 2015, Kraft and H.J. Heinz Holding Corporation (“Heinz”) issued a joint press release announcing their entry into a definitive merger agreement. A copy of the press release is filed as Exhibit 99.1 to this report and incorporated herein by reference.

Cautionary Statements Regarding Forward-Looking Information

Except for the historical information contained herein, certain of the matters discussed in this communication constitute “forward-looking statements” within the meaning of the Securities Act of 1933 and the Securities Exchange Act of 1934, both as amended by the Private Securities Litigation Reform Act of 1995. Words such as “may,” “might,” “will,” “should,” “could,” “anticipate,” “estimate,” “expect,” “predict,” “project,” “future”, “potential,” “intend,” “seek to,” “plan,” “assume,” “believe,” “target,” “forecast,” “goal,” “objective,” “continue” or the negative of such terms or other variations thereof and words and terms of similar substance used in connection with any discussion of future plans, actions, or events identify forward-looking statements. These forward-looking statements include, but are not limited to, statements regarding benefits of the proposed merger, integration plans and expected synergies, anticipated future financial and operating performance and results, including estimates for growth. There are a number of risks and uncertainties that could cause actual results to differ materially from the forward-looking statements included in this communication. For example, the expected timing and likelihood of completion of the pending merger, including the timing, receipt and terms and conditions of any required governmental and regulatory approvals of the pending merger that could reduce anticipated benefits or cause the parties to abandon the transaction, the ability to successfully integrate the businesses, the occurrence of any event, change or other circumstances that could give rise to the termination of the merger agreement, the possibility that Kraft shareholders may not approve the merger agreement, the risk that the parties may not be able to satisfy the conditions to the proposed transaction in a timely manner or at all, risks related to disruption of management time from ongoing business operations due to the proposed transaction, the risk that any announcements relating to the proposed transaction could have adverse effects on the market price of Kraft’s common stock, and the risk that the proposed transaction and its announcement could have an adverse effect on the ability of Kraft and Heinz to retain customers and retain and hire key personnel and maintain relationships with their suppliers and customers and on their operating results and businesses generally, problems may arise in successfully integrating the businesses of the companies, which may result in the combined company not operating as effectively and efficiently as expected, the combined company may be unable to achieve cost-cutting synergies or it may take longer than expected to achieve those synergies, and other factors. All such factors are difficult to predict and are beyond our control. We disclaim and do not undertake any obligation to update or revise any forward-looking statement in this report, except as required by applicable law or regulation.

2

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 transaction between Kraft and Heinz. In connection with the proposed transaction, Heinz intends to file a registration statement on Form S-4, containing a proxy statement/prospectus (the “S-4”) with the Securities and Exchange Commission (“SEC”). This communication is not a substitute for the registration statement, definitive proxy statement/prospectus or any other documents that Heinz or Kraft may file with the SEC or send to shareholders in connection with the proposed transaction. SHAREHOLDERS OF KRAFT 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 TRANSACTION.

Investors and security holders will be able to obtain copies of the S-4, including the proxy statement/prospectus, and other documents filed with the SEC (when available) free of charge at the SEC’s website, http://www.sec.gov. Copies of documents filed with the SEC by Kraft will be made available free of charge on Kraft’s website at http://www.kraftfoodsgroup.com/. Copies of documents filed with the SEC by Heinz will be made available free of charge on Heinz’s website at http://www.heinz.com/.

Participants in the Solicitation

Kraft and its directors and executive officers, and Heinz and its directors and executive officers, may be deemed to be participants in the solicitation of proxies from the holders of Kraft common stock in respect of the proposed transaction. Information about the directors and executive officers of Kraft is set forth in the proxy statement for Kraft’s 2015 Annual Meeting of Shareholders, which was filed with the SEC on March 18, 2015. Information about the directors and executive officers of Heinz will be set forth in the S-4. Investors may obtain additional information regarding the interests of such participants by reading the proxy statement/prospectus regarding the proposed transaction when it becomes available. You may obtain free copies of these documents as described in the preceding paragraph.

3

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