UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 10-Q/A

(Mark One)

For the Quarter ended March 31, 2013

OR

For the transition period from                      to                     

1-35573

(Commission file number)

TRONOX LIMITED

(ACN 153 348 111)

(Exact Name of Registrant as Specified in its Charter)

One Stamford Plaza

263 Tresser Boulevard, Suite 1100

Stamford, Connecticut 06901

Registrant’s telephone number, including area code: (203) 705-3800

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  x    No  ¨

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Website, 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  x    No  ¨

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 the definitions 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  x

As of April 30, 2013, there were 113,339,879 shares of the Registrant’s Class A ordinary shares and Class B ordinary shares outstanding.

Documents incorporated by reference: none.

EXPLANATORY NOTE

The registrant is filing this Amendment No. 1 to Form 10-Q, or this Amendment, to amend the Form 10-Q for the fiscal quarter ended March 31, 2013 (Commission File Number 001–35758), or the Form 10-Q, as filed by the registrant with the Securities and Exchange Commission, or the SEC, on February 28, 2013. The purpose of this Amendment is to amend and restate Item 4. Controls and Procedures for the purpose of disclosing the conclusions of our Chief Executive Officer and principal financial officer regarding the effectiveness of our disclosure controls and procedures as of March 31, 2013. In addition, as required by Rule 12b-15 under the Securities Exchange Act of 1934, as amended, new certifications by the registrant’s principal executive officer and principal financial officer are filed as exhibits to this Amendment

No other changes have been made to the Form 10-Q other than those described above. This Amendment does not reflect subsequent events occurring after the original filing date of the Form 10-Q or modify or update in any way disclosures made in the Form 10-Q.

(a) Disclosure Controls and Procedures

As of March 31, 2013, our management, including our Chief Executive Officer and principal financial officer, have conducted an evaluation of the effectiveness of the design and operation of our disclosure controls and procedures pursuant to Rule 13a-15(b) of the Exchange Act. Based on that evaluation, our Chief Executive Officer and principal financial officer have concluded that our disclosure controls and procedures are effective as of the end of the period covered by this Report.

(b) Changes in Internal Control Over Financial Reporting

There have been no changes in our internal control over financial reporting during the first quarter ended March 31, 2013, that has materially affected, or is reasonably likely to materially affect, our internal control over financial reporting.

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EXHIBIT INDEX

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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, in the City of Stamford, State of Connecticut, on this 31st day of July 2013.

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