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 22, 2013

LEGGETT & PLATT, INCORPORATED

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code 417-358-8131

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 (see General Instruction A.2. below):

On August 22, 2013, we entered into the First Amendment to Credit Agreement among us, JPMorgan Chase Bank, N.A., as administrative agent (“JPMorgan”) and the banking institutions listed below (the “Amendment”). The Amendment modifies our multi-currency revolving credit agreement, dated August 19, 2011 (the “Credit Agreement”). We, from time to time, may borrow, repay and re-borrow up to $600 million until the maturity date, at which time our ability to borrow under the Credit Agreement will terminate.

The Credit Agreement was amended to:

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Below are the lending commitments under the Credit Agreement, as amended.

We may elect the type of borrowing under the amended Credit Agreement, which determines the rate of interest to be paid on the outstanding principal balance, as follows:

We are required to periodically pay accrued interest on any outstanding principal balance under the Credit Agreement at different time intervals based upon the elected interest rate and the elected interest period. Any outstanding principal under the Credit Agreement will be due upon the maturity date.

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We may also terminate or reduce the lending commitments under the Credit Agreement, in whole or in part, upon three business days notice. Our ability to borrow under the Credit Agreement is reduced by the amount of outstanding letters of credit issued pursuant to the Credit Agreement. The amount of letters of credit is limited to $250 million. As of the date hereof, there are no letters of credit outstanding under the Credit Agreement.

The Credit Agreement is unsecured, but contains restrictive covenants which, among other things, limit (i) our total indebtedness to 60% of our total capital (each as defined in the Credit Agreement), (ii) the amount of secured debt to 15% of consolidated total assets, and (iii) the amount of assets sold, transferred or leased (other than products sold in the ordinary course) in any trailing four quarter period to 20% of consolidated total assets as of the most recent fiscal year-end.

Subject to certain customary cure periods, the Credit Agreement provides that if we breach any representation or warranty, do not comply with any covenant, fail to pay principal, interest or fees in a timely manner, or if any Event of Default (as defined in the Credit Agreement) otherwise occurs, then the Credit Agreement may be terminated. Upon termination, all outstanding indebtedness under the Credit Agreement will accelerate.

The Credit Agreement acts as support for the marketability of our $600 million commercial paper program. As of August 22, 2013, the Company had $186 million of commercial paper outstanding. There are currently no borrowings under the Credit Agreement. Although we do not anticipate borrowing directly under the Credit Agreement, we can do so independently from the commercial paper program.

The foregoing is only a summary of certain terms of the Credit Agreement and the Amendment and is qualified in its entirety by reference to: (a) the Credit Agreement, dated August 19, 2011 among us, JPMorgan, as administrative agent, and the participating banking institutions named therein, which was filed August 19, 2011 as Exhibit 10.1 to our Form 8-K and is incorporated herein by reference; and (b) the First Amendment to Credit Agreement, dated August 22, 2013, which is attached hereto as Exhibit 10.2 and incorporated herein by reference.

The listed banks and/or their affiliates have provided, from time to time, and may continue to provide commercial banking and related services, as well as investment banking, financial advisory and other services to us and/or to our affiliates, for which we have paid, and intend to pay, customary fees, and, in some cases, out-of-pocket expenses.

The information provided in Item 1.01 above is incorporated herein by reference.

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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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