| Cover | Nov. 11, 2024 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Nov. 11, 2024 |
| Entity File Number | 001-41534 |
| Entity Registrant Name | Citius Oncology, Inc. |
| Entity Central Index Key | 0001851484 |
| Entity Tax Identification Number | 99-4362660 |
| Entity Incorporation, State or Country Code | DE |
| Entity Address, Address Line One | 11 Commerce Drive |
| Entity Address, Address Line Two | 1st Floor |
| Entity Address, City or Town | Cranford |
| Entity Address, State or Province | NJ |
| Entity Address, Postal Zip Code | 07016 |
| City Area Code | 908 |
| Local Phone Number | 967-6677 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock |
| Trading Symbol | CTOR |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | true |
| Elected Not To Use the Extended Transition Period | false |
