Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2022	Jul. 29, 2022
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2022
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q2
Entity Registrant Name	ORCHARD THERAPEUTICS PLC
Current Fiscal Year End Date	--12-31
Entity Central Index Key	0001748907
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Common Stock, Shares Outstanding		126,458,312
Entity Shell Company	false
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Incorporation, State or Country Code	X0
Entity Address, Address Line One	108 Cannon Street
Entity Address, City or Town	London
Entity Address, Postal Zip Code	EC4N 6EU
City Area Code	44
Local Phone Number	(0) 203 808-8286
Document Quarterly Report	true
Document Transition Report	false
Entity File Number	001-38722
Entity Emerging Growth Company	false
Entity Tax Identification Number	00-0000000
Entity Address, Country	GB
Title of 12(b) Security	American Depositary Shares, each representing oneordinary share, nominal value £0.10 per share
Trading Symbol	ORTX
Security Exchange Name	NASDAQ