UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K/A

Amendment No. 1

(Mark One)

For the fiscal year ended December 31, 2014

OR

For the transition period from          to         

Commission File Number 001-34658

(Exact name of registrant as specified in its charter)

Registrant’s Telephone Number, Including Area Code: (704) 625-4900

Securities Registered Pursuant to Section 12(b) of the Act:

Securities registered pursuant to Section 12(g) of the Act: None

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.    Yes  þ    No  ¨

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Exchange Act.    Yes  ¨    No  þ

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.    Yes  þ    No  ¨

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).    Yes  þ    No  ¨

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K is not contained herein and will not be contained, to the best of registrant’s knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K.    þ

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See definition of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act. (Check one):

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).    Yes  ¨    No  þ

The aggregate market value of the registrant’s common stock held by nonaffiliates of the registrant on the last business day of the registrant’s most recently completed second fiscal quarter (based on the closing sales price on the New York Stock Exchange on June 30, 2014) was approximately $3.6 billion.

The number of shares of the registrant’s common stock outstanding at January 31, 2015 was 106,710,346.

EXPLANATORY NOTE

The sole purpose of this Amendment No. 1 on Form 10-K/A (the “Form 10-K/A”) to our Annual Report on Form 10-K for the year ended December 31, 2014 originally filed with the Securities and Exchange Commission on February 25, 2015 (the “Form 10-K”), is to correct the number of shares of our common stock outstanding at January 31, 2015 on the cover page of such Form 10-K. The correct number of shares of our common stock outstanding at January 31, 2015 was 106,710,346.

This Form 10-K/A has not been updated for events occurring after the filing of the Form 10-K, and no attempt has been made in this Form 10-K/A to modify or update other disclosures as presented in the original filing of our Form 10-K.

PART IV

The following documents are filed as part of the Annual Report on Form 10-K of The Babcock & Wilcox Company for the year ended December 31, 2014, as amended by this Amendment No. 1 on Form 10-K/A:

SIGNATURES

Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

INDEX TO EXHIBITS