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): November 1, 2016

WALGREENS BOOTS ALLIANCE, INC.

(Exact Name of Registrant as Specified in Its Charter)

Registrant’s Telephone Number, Including Area Code: (847) 315-2500

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 November 1, 2016, Walgreens Boots Alliance, Inc. (the “Company”) announced that affiliates of Kohlberg Kravis Roberts & Co. L.P. (“KKR,” and together, the “Selling Stockholders”) intend to offer for sale in an underwritten secondary offering (the “Offering”) 20,461,215 shares of the Company’s common stock pursuant to the automatically effective shelf registration statement filed by the Company with the Securities and Exchange Commission (the “SEC”) on February 17, 2016. In addition, separate and apart from the proposed Offering, the Selling Stockholders and Stefano Pessina, the Company’s Executive Vice Chairman and Chief Executive Officer, informed the Company that they have entered into an agreement on October 31, 2016, pursuant to which the Selling Stockholders have agreed to sell 2,000,000 shares of the Company’s common stock to an affiliate of Mr. Pessina at the same price as the shares to be sold to the underwriter in the proposed Offering, and subject to the completion of the proposed Offering. Prior to the proposed Offering, the Selling Stockholders owned 22,461,215 shares in the aggregate, representing approximately 2.1 percent of the Company’s outstanding shares of common stock, based on the number of shares outstanding as of September 30, 2016. Upon completion of the proposed Offering and the separate proposed sale of shares by the Selling Stockholders to an affiliate of Mr. Pessina, the Selling Stockholders will no longer own any remaining shares of the Company’s common stock previously issued to the Selling Stockholders in connection with the Company’s strategic combination with Alliance Boots GmbH.

A copy of the press release issued by the Company, dated November 1, 2016, announcing the secondary Offering is attached to this Current Report on Form 8-K as Exhibit 99.1 and is incorporated by reference into this Item 8.01.

Cautionary Statement Regarding Forward-Looking Statements

This Current Report on Form 8-K contains forward-looking statements that are based on current expectations, estimates, forecasts and projections about our future performance, our business, our beliefs and our management’s assumptions. In addition, we, or others on our behalf, may make forward-looking statements in press releases or written statements, on the Company’s website or in our communications and discussions with investors and analysts in the normal course of business through meetings, webcasts, phone calls, conference calls and other communications. Some of such forward-looking statements may be based on certain data and forecasts relating to our business and industry that we have obtained from internal surveys, market research,

publicly available information and industry publications. Industry publications, surveys and market research generally state that the information they provide has been obtained from sources believed to be reliable, but that the accuracy and completeness of such information is not guaranteed. Statements that are not historical facts are forward-looking statements, including, without limitation, those regarding estimates of and goals for future financial and operating performance as well as forward-looking statements concerning the expected execution and effect of our business strategies, our cost-savings and growth initiatives and restructuring activities and the amounts and timing of their expected impact, our pending Merger Agreement with Rite Aid and the transactions contemplated thereby and their possible effects, our commercial agreement with AmerisourceBergen, the arrangements and transactions contemplated by our framework agreement with AmerisourceBergen and their possible effects, estimates of the impact of developments on our earnings, earnings per share and other financial and operating metrics, cough, cold and flu season, prescription volume, pharmacy sales trends, prescription margins, changes in generic prescription drug prices, retail margins, number and location of new store openings, network participation, vendor, payer and customer relationships and terms, possible new contracts or contract extensions, the proposed withdrawal of the United Kingdom from the European Union and its possible effects, competition, economic and business conditions, outcomes of litigation and regulatory matters, the level of capital expenditures, industry trends, demographic trends, growth strategies, financial results, cost reduction initiatives, impairment or other charges, acquisition and joint venture synergies, competitive strengths and changes in legislation or regulations. Words such as “expect,” “likely,” “outlook,” “forecast,” “preliminary,” “would,” “could,” “should,” “can,” “will,” “project,” “intend,” “plan,” “goal,” “guidance,” “target,” “aim,” “continue,” “sustain,” “synergy,” “on track,” “on schedule,” “headwind,” “tailwind,” “believe,” “seek,” “estimate,” “anticipate,” “may,” “possible,” “assume,” and variations of such words and similar expressions are intended to identify such forward-looking statements, which are made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995.

These forward-looking statements are not guarantees of future performance and are subject to risks, uncertainties and assumptions, known or unknown, that could cause actual results to vary materially from those indicated or anticipated, including, but not limited to, those relating to the impact of private and public third-party payers’ efforts to reduce prescription drug reimbursements, fluctuations in foreign currency exchange rates, the timing and magnitude of the impact of branded to generic drug conversions and changes in generic drug prices, our ability to realize synergies and achieve financial, tax and operating results in the amounts and at the times anticipated, supply arrangements including our commercial agreement with AmerisourceBergen, the arrangements and transactions contemplated by our framework agreement with AmerisourceBergen and their possible effects, our equity method investment in AmerisourceBergen, the occurrence of any event, change or other circumstance that could give rise to the termination, cross-termination or modification of any of our contractual obligations, the amount of costs, fees, expenses and charges incurred in connection with strategic transactions, whether the costs associated with restructuring activities will exceed estimates, our ability to realize expected savings and benefits from cost-savings initiatives, restructuring activities and acquisitions in the amounts and at the times anticipated, the timing and amount of any impairment or other charges, the timing and severity of cough, cold and flu season, changes in management’s assumptions, the risks associated with governance and control matters, the ability to retain key personnel, changes in economic and business conditions generally or in particular markets in which we participate,

changes in financial markets and interest rates, the risks associated with international business operations, including the risks associated with the proposed withdrawal of the United Kingdom from the European Union, the risk of unexpected costs, liabilities or delays, changes in vendor, customer and payer relationships and terms, including changes in network participation and reimbursement terms, risks of inflation in the cost of goods, risks associated with the operation and growth of our customer loyalty programs, competition, risks associated with new business areas and activities, risks associated with acquisitions, divestitures, joint ventures and strategic investments, including those relating to our ability to satisfy the closing conditions and consummate the pending acquisition of Rite Aid and related matters on a timely basis or at all, the risks associated with the integration of complex businesses, outcomes of legal and regulatory matters, including with respect to regulatory review and actions in connection with the pending acquisition of Rite Aid, and changes in legislation, regulations or interpretations thereof. These and other risks, assumptions and uncertainties are described in Item 1A “Risk Factors” of our Annual Report on Form 10-K for the fiscal year ended August 31, 2016 and in other documents that we file or furnish with the SEC. Should one or more of these risks or uncertainties materialize, or should underlying assumptions prove incorrect, actual results may vary materially from those indicated or anticipated by such forward-looking statements. Accordingly, you are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date they are made. Except to the extent required by law, we do not undertake, and expressly disclaim, any duty or obligation to update publicly any forward-looking statement after the date the statement is made, whether as a result of new information, future events, changes in assumptions 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 thereunto duly authorized.

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