| Document and Entity Information | Sep. 23, 2021 |
| Document Document And Entity Information [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Sep. 23, 2021 |
| Entity Registrant Name | KINTARA THERAPEUTICS, INC. |
| Entity Central Index Key | 0001498382 |
| Entity Incorporation, State or Country Code | NV |
| Entity File Number | 001-37823 |
| Entity Tax Identification Number | 99-0360497 |
| Entity Address, Address Line One | 12707 High Bluff Dr. |
| Entity Address, Address Line Two | Suite 200 |
| Entity Address, City or Town | San Diego |
| Entity Address, State or Province | CA |
| Entity Address, Postal Zip Code | 92130 |
| City Area Code | 858 |
| Local Phone Number | 350-4364 |
| 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 | KTRA |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
