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 6, 2013

rue21, inc.

(Exact Name of Registrant as Specified in its Charter)

(724) 776-9780

(Registrant’s telephone number including area code)

(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:

Item 7.01 Regulation FD Disclosure

rue21, inc. (“rue21” or the “Company”) is disclosing under Item 7.01 of this Current Report on Form 8-K the information attached to this report as Exhibit 99.1, which information is incorporated herein by reference. This information, portions of which have not been previously reported, is excerpted from certain materials that are or will be disseminated to prospective investors in connection with the syndication by Rhodes Merger Sub, Inc. or one or more of its subsidiaries, of up to $533 million in aggregate principal amount of a senior secured term loan in connection with the previously announced merger agreement, dated as of May 23, 2013, by and among the Company, Rhodes Holdco, Inc., and Rhodes Merger Sub, Inc., a wholly-owned subsidiary of Rhodes Holdco, Inc. Rhodes Holdco, Inc. and Rhodes Merger Sub, Inc. are beneficially owned by affiliates of Apax Partners, L.P.

As provided in General Instruction B.2 of Form 8-K, the information included under this Item, including Exhibit 99.1, shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, nor shall it be deemed to be incorporated by reference in any filing under the Securities Act of 1933, except as shall be expressly set forth by specific reference in such a filing.

Forward-Looking Statements

This communication may include predictions, estimates and other information that might be considered forward-looking statements, including, without limitation, statements relating to the completion of this transaction. These statements are based on current expectations and assumptions that are subject to risks and uncertainties. Actual results could differ materially from those anticipated as a result of various factors, including: (1) rue21 may be unable to obtain stockholder approval as required for the transaction; (2) conditions to the closing of the transaction may not be satisfied; (3) the transaction may involve unexpected costs, liabilities or delays; (4) the business of rue21 may suffer as a result of uncertainty surrounding the transaction; (5) the outcome of any legal proceedings related to the transaction; (6) rue21 may be adversely affected by other economic, business, and/or competitive factors; (7) the occurrence of any event, change or other circumstances that could give rise to the termination of the transaction agreement; (8) the ability to recognize benefits of the transaction; (9) risks that the transaction disrupts current plans and operations and the potential difficulties in employee retention as a result of the transaction; and (10) other risks to consummation of the transaction, including the risk that the transaction will not be consummated within the expected time period or at all. Additional factors that may affect the future results of rue21 are set forth in its filings with the Securities and Exchange Commission (the “SEC”), including its Annual Report on Form 10-K for the year ended February 2, 2013, which is available on the SEC’s website at www.sec.gov. Readers are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date thereof. Except as required by applicable law, rue21 undertakes no obligation to update forward-looking statements to reflect events or circumstances after the date thereof.

Item 9.01 Financial Statements and Exhibits

(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.

August 6, 2013

EXHIBIT INDEX

4