Cover - shares	3 Months Ended
	Mar. 28, 2025	Apr. 25, 2025
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 28, 2025
Document Transition Report	false
Entity File Number	000-50646
Entity Registrant Name	Ultra Clean Holdings, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	61-1430858
Entity Address, Address Line One	26462 Corporate Avenue
Entity Address, City or Town	Hayward
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94545
City Area Code	510
Local Phone Number	576-4400
Title of 12(b) Security	Common stock, par value $0.001 per share
Trading Symbol	UCTT
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		45,149,090
Amendment Flag	false
Document Fiscal Year Focus	2025
Document Fiscal Period Focus	Q1
Entity Central Index Key	0001275014
Current Fiscal Year End Date	--12-26