X0306 4 2016-12-01 0 0000106040 WESTERN DIGITAL CORP WDC 0001277246 MILLIGAN STEPHEN D C/O WESTERN DIGITAL CORPORATION 3355 MICHELSON DRIVE, SUITE 100 IRVINE CA 92612 1 1 0 0 Chief Executive Officer Common Stock 2016-12-01 4 S 0 67 65 D 105441 D Common Stock 22500 I By Family Trust The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on June 10, 2016. Includes 123 shares acquired under the issuer's Employee Stock Purchase Plan on November 30, 2016. Reflects a change in form of beneficial ownership of shares of Issuer's common stock with respect to 67 shares that were transferred from the reporting person's Family Trust account to the reporting person's brokerage account and sold by the reporting person as reported herein. /s/Sandra Garcia Attorney-in-Fact for Stephen D. Milligan 2016-12-05