Document And Entity Information - shares	6 Months Ended
	Jun. 30, 2021	Aug. 06, 2021
Document Information [Line Items]
Entity Central Index Key	0001488039
Entity Registrant Name	ATOSSA THERAPEUTICS, INC.
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	Q2
Document Fiscal Year Focus	2021
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2021
Document Transition Report	false
Entity File Number	001-35610
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	26-4753208
Entity Address, Address Line One	107 Spring Street
Entity Address, Postal Zip Code	98104
Entity Address, City or Town	Seattle
Entity Address, State or Province	WA
City Area Code	206
Local Phone Number	325-6086
Title of 12(b) Security	Common Stock, $0.18 par value
Trading Symbol	ATOS
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		126,623,256