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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 10-K/A

Amendment No. 1

(Mark One)

For the fiscal year ended January 30, 2016

or

For the transition period from              to             

Commission file number 0-30877

Marvell Technology Group Ltd.

(Exact name of registrant as specified in its charter)

Canon’s Court, 22 Victoria Street, Hamilton HM 12, Bermuda

(Address of principal executive offices)

(441) 296-6395

(Registrant’s telephone number, including area code)

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  ¨    No  x

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

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 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  x    No  ¨

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K (§229.405 of this chapter) is not contained herein, and will not be contained, to the best of the 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.  x

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

The aggregate market value of the registrant’s common shares held by non-affiliates of the registrant was approximately $4,380 million based upon the closing price of $12.44 per share on the NASDAQ Global Select Market on July 31, 2015 (the last business day of the registrant’s most recently completed second quarter). Common shares held by each director and executive officer of the registrant, as well as shares held by each holder of more than 5% of the common shares known to the registrant (based on Schedule 13G filings), have been excluded for purposes of the foregoing calculation.

As of July 29, 2016, there were 511.2 million common shares of the registrant outstanding.

DOCUMENTS INCORPORATED BY REFERENCE

None

TRADEMARKS

Marvell^®, Alaska^®, ARMADA^® Avanta^®, Avastar^®, Kirkwood^®, Link Street^®, Prestera^®, Xelerated^® and Yukon^® are registered trademarks of Marvell International Ltd. and/or its affiliates. Any other trademarks or trade names mentioned are the property of their respective owners.

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PART IV

See the “Index to Consolidated Financial Statements” on page 57 of the originally filed Annual Report on Form 10-K for the fiscal year ended January 30, 2016 as filed with the SEC on July 21, 2016.

All other schedules not listed above have been omitted because they are not applicable or required, or the information required to be set forth therein is included in the Consolidated Financial Statements or Notes thereto.

See the “Index to Exhibits” immediately following the signature page of this Annual Report on Form 10-K/A Amendment No. 1.

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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.

Pursuant to the requirements of the Securities Exchange Act of 1934, this report has been signed by the following persons on behalf of the registrant in the capacities and on the dates indicated.

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INDEX TO EXHIBITS

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