Cover Page - shares	9 Months Ended
	Sep. 30, 2020	Nov. 04, 2020
Cover [Abstract]
Document Type	10-Q
Entity Interactive Data Current	Yes
Amendment Flag	false
Document Period End Date	Sep. 30, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q3
Entity Registrant Name	Neoleukin Therapeutics, Inc.
Trading Symbol	NLTX
Entity Central Index Key	0001404644
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Title of 12(b) Security	Common Stock, par value $0.000001
Entity Incorporation, State or Country Code	DE
Security Exchange Name	NASDAQ
Entity Common Stock, Shares Outstanding		41,894,382
Entity File Number	001-36327
Entity Tax Identification Number	98-0542593
Entity Address, Address Line One	360-1616 Eastlake Avenue East
Entity Address, City or Town	Seattle
Entity Address, State or Province	WA
Entity Address, Postal Zip Code	98102
City Area Code	(206)
Local Phone Number	732-2133
Document Quarterly Report	true
Document Transition Report	false