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 14, 2011 (November 7, 2011)

PEABODY ENERGY CORPORATION

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code (314) 342-3400

N/A

(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 7, 2011, Peabody Energy Corporation “Peabody” issued a press release announcing the pricing of its offering of $1.6 billion aggregate principal amount of 6.00% Senior Notes due 2018 and $1.5 billion aggregate principal amount of 6.25% Senior Notes due 2021. Peabody intends to use the net proceeds from the sale of the notes, together with other sources of financing, to fund the acquisition of Macarthur Coal Limited and for related fees and expenses, with any remaining proceeds being used to repay part or all of any revolver borrowings associated with the acquisition or for general corporate purposes. A copy of the press release is attached hereto as Exhibit 99.1 and is incorporated herein by reference.

Forward-Looking Statements

This report and the exhibit hereto may contain certain statements that are forward-looking statements within the meaning of Section 27A of the Securities Act and Section 21E of the Exchange Act. Wherever possible, Peabody has identified these forward-looking statements by words such as “anticipates,” “believes,” “intends,” “estimates,” “expects,” “projects” and similar phrases. These forward-looking statements are based upon assumptions its management believes are reasonable. Such forward-looking statements are subject to risks and uncertainties which could cause Peabody’s actual results, performance and achievements to differ materially from those expressed in, or implied by, these statements, including, among other things, the risks and uncertainties disclosed in its Annual Report on Form 10-K, its Quarterly Reports on Form 10-Q and other reports it files with the Securities and Exchange Commission from time to time.

Because these forward-looking statements are based on estimates and assumptions that are subject to significant business, economic and competitive uncertainties, many of which are beyond Peabody’s control or are subject to change, actual results could be materially different and any or all of these forward-looking statements may turn out to be wrong. They speak only as of the date made and can be affected by assumptions Peabody might make, or by known or unknown risks and uncertainties. Many factors mentioned in this document and the exhibit hereto and in

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Peabody’s annual and quarterly reports will be important in determining future results. Consequently, Peabody cannot assure you that its expectations or forecasts expressed in such forward-looking statements will be achieved. Actual future results may vary materially. Except as required by law, Peabody undertakes no obligation to publicly update any of its forward-looking or other statements, whether as a result of new information, future events, or otherwise.

(d) Exhibits.

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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.

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EXHIBIT INDEX

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