Air Products & Chemicals Inc (APD): Bill Ackman Unloads 3.58 Million Shares

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Schedule 13D

(Rule 13d-101)

INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT

TO RULE 13d-1(a) AND AMENDMENTS THERETO FILED PURSUANT TO

RULE 13d-2(a)

Under the
Securities Exchange Act of 1934

(Amendment No. 3)*

Air Products and Chemicals, Inc.

(Name of Issuer)

Common
Stock

(Title of Class of Securities)

009158106

(CUSIP Number)

Steve Fraidin, Esq.

Steve Milankov, Esq.

Pershing Square Capital Management, L.P.

888 Seventh Avenue, 42nd Floor

New York, New York 10019

212-813-3700

With a
Copy to:

Richard M. Brand, Esq.

Cadwalader, Wickersham & Taft LLP

One World Financial Center

New York, NY 10281

212-504-5757

(Name,
Address and Telephone Number of Person Authorized to Receive Notices and Communications)

September 12, 2016

(Date of Event which Requires Filing of this Statement)

If the filing
person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of Rule 13d-1(e), 13d-1(f) or 13d-1(g), check the following box.  ¨

Note: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See Rule 13d-7 for
other parties to whom copies are to be sent.

The information required on the remainder of this cover page
shall not be deemed to be filed for the purpose of Section 18 of the Securities Exchange Act of 1934 (Act) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other
provisions of the Act (however, see the Notes).

SCHEDULE 13D

SCHEDULE 13D

SCHEDULE 13D

SCHEDULE 13D

SCHEDULE 13D

This Amendment No. 3 to Schedule 13D (this Amendment No.
3) amends and supplements the statement on Schedule 13D (the Original Schedule 13D), filed on July 31, 2013 (the Original Schedule 13D, as amended and supplemented through the date of this Amendment No. 3, the
Schedule 13D), by Pershing Square Capital Management, L.P., a Delaware limited partnership (Pershing Square); PS Management GP, LLC, a Delaware limited liability company (PS Management); PS V
GP, LLC, a Delaware limited liability company (PSV GP); and William A. Ackman, a citizen of the United States of America (together with Pershing Square, PS Management, and PSV GP, the Reporting Persons),
relating to the common stock, par value $1.00 per share (the Common Stock), of Air Products and Chemicals, Inc., a Delaware corporation (the Issuer). Capitalized terms used but not
defined in this Amendment No. 3 shall have the meanings set forth in the Schedule 13D. The principal executive offices of the Issuer are located at: 7201 Hamilton Boulevard, Allentown, Pennsylvania 18195-1501.

As of September 12, 2016, the Reporting Persons beneficially owned an aggregate of 16,973,076 shares of Common Stock, representing
approximately 7.8% of the outstanding shares of Common Stock of the Issuer. This number includes 4,025,140 shares of Common Stock, and 12,947,936 shares of Common Stock underlying over-the-counter American-style call options.

Except as specifically amended by this Amendment No. 3, items in the Schedule 13D are unchanged.

Item 4 of the Schedule 13D is hereby amended and supplemented by adding the
following information:

The three-year commitment period for Pershing Squares co-investment vehicles in the Issuer (the PSV
Funds) ends on September 30, 2016. The Reporting Persons sold the Common Stock listed in Exhibit 99.6 to return capital to the PSV Funds co-investors.

Item 5 of the Schedule 13D is hereby amended and supplemented by
adding the following information:

(a), (b) The Reporting Persons beneficially own an aggregate of 16,973,076 shares of Common Stock (the
Subject Shares), which number includes: 4,025,140 shares of Common Stock and 12,947,936 shares of Common Stock underlying over-the-counter American-style call options. The number of Subject Shares is 3,576,000 lower than
the number reported in the last Amendment to the Original Schedule 13D as a result of sales of shares of the Issuers Common Stock. The Subject Shares beneficially owned by the Reporting Persons represent approximately 7.8% of the shares
of Common Stock issued and outstanding (based upon 216,549,704 shares stated to be outstanding as of June 30, 2016 by the Issuer in its Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission on July 29, 2016).

(c) Exhibit 99.6, which is incorporated by reference into this Item 5 as if restated in full, describes all of the transactions in the Common
Stock (or options relating to Common Stock) that were effected in the past 60 days by the Reporting Persons for the benefit of the Pershing Square Funds. Except as set forth in Exhibit 99.6, no reportable transactions were effected by any
Reporting Person within the last 60 days.

SCHEDULE 13D

Item 7 of the Schedule 13D is hereby amended and supplemented by
adding the following exhibits:

SCHEDULE 13D

SIGNATURES

After reasonable inquiry and to the best of each of the undersigneds knowledge and belief, each of the undersigned certify that the
information set forth in this statement is true, complete and correct.

Date: September 13, 2016

SCHEDULE 13D

EXHIBIT INDEX