Cover Page - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Mar. 12, 2020	Jun. 30, 2019
Cover [Abstract]
Document Type	10-K
Entity Interactive Data Current	Yes
Amendment Flag	false
Document Period End Date	Dec. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Entity Registrant Name	Neoleukin Therapeutics, Inc.
Trading Symbol	NLTX
Entity Central Index Key	0001404644
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity Filer Category	Non-accelerated Filer
Entity Voluntary Filers	No
Entity Small Business	true
Entity Emerging Growth Company	false
Title of 12(b) Security	Common Stock
Entity Address, State or Province	DE
Security Exchange Name	NASDAQ
Entity Public Float			$ 24.2
Entity Common Stock, Shares Outstanding		38,373,160