| Document And Entity Information | 9 Months Ended |
| Sep. 30, 2023 | |
| Document Information Line Items | |
| Entity Registrant Name | Allarity Therapeutics, Inc. |
| Document Type | S-1/A |
| Amendment Flag | true |
| Amendment Description | AMENDMENT NO. 2 |
| Entity Central Index Key | 0001860657 |
| Entity Filer Category | Non-accelerated Filer |
| Entity Small Business | true |
| Entity Emerging Growth Company | true |
| Entity Ex Transition Period | false |
| Entity Incorporation, State or Country Code | DE |
