Cover Page - shares	9 Months Ended
	Apr. 02, 2021	Apr. 29, 2021
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Apr. 02, 2021
Document Transition Report	false
Entity File Number	1-8703
Entity Registrant Name	WESTERN DIGITAL CORPORATION
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	33-0956711
Entity Address, Address Line One	5601 Great Oaks Parkway
Entity Address, City or Town	San Jose,
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	95119
City Area Code	408
Local Phone Number	717-6000
Title of 12(b) Security	Common Stock, $.01 Par Value Per Share
Trading Symbol	WDC
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		306,452,886
Entity Central Index Key	0000106040
Current Fiscal Year End Date	--07-02
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Amendment Flag	false