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): October 7, 2013 (October 4, 2013)

MEMORIAL PRODUCTION PARTNERS LP

(Exact Name of Registrant as Specified in Charter)

Registrant’s telephone number, including area code: (713) 588-8300

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:

¨ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

¨ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

¨ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

¨ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

On October 7, 2013, Memorial Production Partners LP (the “Partnership”) issued a press release announcing that, subject to market conditions, the Partnership intended to offer senior unsecured notes due 2021 in a private offering to eligible purchasers. A copy of the press release is filed as Exhibit 99.1 to this Current Report on Form 8-K and is incorporated in this Item 8.01 by reference.

Pursuant to the underwriting agreement, dated October 2, 2013, among the Partnership, Memorial Production Partners GP LLC (the “General Partner”) and Memorial Production Operating LLC and Merrill Lynch, Pierce, Fenner & Smith Incorporated, Barclays Capital Inc., Citigroup Global Markets Inc., Goldman, Sachs & Co., J.P. Morgan Securities LLC, Raymond James & Associates, Inc., RBC Capital Markets, LLC, UBS Securities LLC and Wells Fargo Securities, LLC, as representatives of the several underwriters named therein (collectively, the “Underwriters”), providing for the offer and sale by the Partnership (the “Offering”), and purchase by the Underwriters, of 14,500,000 common units representing limited partner interests in the Partnership (the “Common Units”) at a price to the public of $19.90 per Common Unit ($19.12 per Common Unit, net of underwriting discounts), the Underwriters exercised their option to purchase an additional 2,175,000 Common Units on the same terms on October 4, 2013. Giving effect to the exercise of the Underwriters’ option, the net proceeds of the Offering, including the General Partner’s proportionate capital contribution and after deducting underwriting discounts and commissions but before estimated expenses, will be approximately $319.2 million.

This Current Report on Form 8-K shall not constitute an offer to sell or the solicitation of an offer to buy, nor shall there be any sale of securities mentioned in this Current Report on Form 8-K in any state in which the offer, solicitation or sale would be unlawful. The notes mentioned in this Current Report on Form 8-K have not been registered under the Securities Act of 1933, as amended, or any state securities laws and may not be offered or sold in the United States absent registration or an applicable exemption from registration requirements.

(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