| Document And Entity Information | Feb. 20, 2024 |
| Document Information [Line Items] | |
| Entity, Registrant Name | MONOPAR THERAPEUTICS INC. |
| Document, Type | 8-K |
| Document, Period End Date | Feb. 20, 2024 |
| Entity, Incorporation, State or Country Code | DE |
| Entity, File Number | 001-39070 |
| Entity, Tax Identification Number | 32-0463781 |
| Entity, Address, Address Line One | 1000 Skokie Blvd. |
| Entity, Address, Address Line Two | Suite 350 |
| Entity, Address, City or Town | Wilmette |
| Entity, Address, State or Province | IL |
| Entity, Address, Postal Zip Code | 60091 |
| City Area Code | 847 |
| Local Phone Number | 388-0349 |
| Title of 12(b) Security | Common Stock, $0.001 par value |
| Trading Symbol | MNPR |
| Security Exchange Name | NASDAQ |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity, Emerging Growth Company | true |
| Entity, Ex Transition Period | true |
| Amendment Flag | false |
| Entity, Central Index Key | 0001645469 |
