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): August 5, 2014

ACTAVIS plc

(Exact Name of Registrant as Specified in Charter)

1 Grand Canal Square, Docklands

Dublin 2, Ireland

(Address of Principal Executive Offices)

(862) 261-7000

(Registrant’s telephone number, including area code)

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 (see General Instruction A.2. below):

On August 5, 2014, Actavis plc (the “Company”) announced that beginning with the second quarter of 2014, the Company is presenting its Actavis Pharma Segment Revenues inclusive of the results of key North American promoted brands.

Exhibit 99.1 to this Form 8-K provides Actavis Pharma Segment Revenue inclusive of the results of key North American promoted brands for the three months ended June 30, 2014, March 31, 2014, December 31, 2013, September 30, 2013, June 30, 2013 and March 31, 2013, the six months ended June 30, 2014 and the twelve months ended December 31, 2013, December 31, 2012 and December 31, 2011. The attached Exhibit 99.1 does not represent a restatement of previously issued financial statements and does not affect the Company’s reported net income, earnings per share, total assets, or stockholders’ equity for any of the previously reported periods. The information contained in this Form 8-K is being furnished pursuant to Regulation FD in order to provide the financial community with historical financial data that is presented on a basis consistent with the Company’s additional reporting.

In accordance with General Instruction B.2 of Form 8-K, the information in this Current Report on Form 8-K, shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liability of that section, and shall not be incorporated by reference into any registration statement or other document filed under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such filing.

d. 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.

EXHIBIT INDEX