UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, DC 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 27, 2015

SILICON LABORATORIES INC.

(Exact Name of Registrant as Specified in Charter)

Registrant’s telephone number, including area code: (512) 416-8500

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):

¨ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

¨ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

¨ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

¨ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Item 8.01. Other Events

On August 27, 2015, the Board of Directors of Silicon Laboratories Inc. (“Silicon Laboratories”) authorized a new program to repurchase up to $100 million of Silicon Laboratories common stock through fiscal 2016. The program allows for repurchases to be made in the open market or in private transactions, including structured or accelerated transactions, subject to applicable legal requirements and market conditions. A copy of the press release announcing the share repurchase program is attached as Exhibit 99 to this report.

Item 9.01. Financial Statements and Exhibits

(d) Exhibits.

99                       Press Release of Silicon Laboratories Inc. dated August 27, 2015

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SIGNATURE

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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Exhibit 99

NEWS BRIEF

SILICON LABS’ BOARD OF DIRECTORS AUTHORIZES NEW $100 MILLION SHARE REPURCHASE PROGRAM

AUSTIN, Texas — August 27, 2015 — Silicon Labs (NASDAQ: SLAB), a leading provider of silicon, software and system solutions for the Internet of Things (IoT), today announced that its board of directors approved a new share repurchase program that authorizes management to buy back up to $100 million of the Company’s common stock through fiscal year 2016. The new program is additive to the remainder of the Company’s previous $100 million share repurchase program, with $47 million remaining as of August 25, 2015.

Silicon Labs

Silicon Labs (NASDAQ: SLAB) is a leading provider of silicon, software and system solutions for the Internet of Things, Internet infrastructure, industrial automation, consumer and automotive markets. We solve the electronics industry’s toughest problems, providing customers with significant advantages in performance, energy savings, connectivity and design simplicity. Backed by our world-class engineering teams with unsurpassed software and mixed-signal design expertise, Silicon Labs empowers developers with the tools and technologies they need to advance quickly and easily from initial idea to final product. www.silabs.com

Note to editors: Silicon Laboratories, Silicon Labs, the “S” symbol, the Silicon Laboratories logo and the Silicon Labs logo are trademarks of Silicon Laboratories Inc. All other product names noted herein may be trademarks of their respective holders.

CONTACT: Silicon Labs, Investor Relations: Jalene Hoover +1 512-428-1610, investor.relations@silabs.com