Cover - shares	3 Months Ended
	Dec. 31, 2024	Feb. 11, 2025
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Entity Interactive Data Current	Yes
Amendment Flag	false
Document Period End Date	Dec. 31, 2024
Document Fiscal Year Focus	2025
Document Fiscal Period Focus	Q1
Entity Information [Line Items]
Entity Registrant Name	Citius Oncology, Inc.
Entity Central Index Key	0001851484
Entity File Number	001-41534
Entity Tax Identification Number	99-4362660
Entity Incorporation, State or Country Code	DE
Current Fiscal Year End Date	--09-30
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Contact Personnel [Line Items]
Entity Address, Address Line One	11 Commerce Drive
Entity Address, Address Line Two	First Floor
Entity Address, City or Town	Cranford
Entity Address, State or Province	NJ
Entity Address, Postal Zip Code	07016
Entity Phone Fax Numbers [Line Items]
City Area Code	(908)
Local Phone Number	967-6677
Entity Listings [Line Items]
Title of 12(b) Security	Common stock, $0.0001 par value
Trading Symbol	CTOR
Security Exchange Name	NASDAQ
Entity Common Stock, Shares Outstanding		71,552,402