| Document and Entity Information | Aug. 08, 2023 |
| Cover [Abstract] | |
| Amendment Flag | false |
| Entity Central Index Key | 0001878313 |
| Document Type | 8-K |
| Document Period End Date | Aug. 08, 2023 |
| Entity Registrant Name | MAIA Biotechnology, Inc. |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 001-41455 |
| Entity Tax Identification Number | 83-1495913 |
| Entity Address, Address Line One | 444 West Lake Street |
| Entity Address, Address Line Two | Suite 1700 |
| Entity Address, City or Town | Chicago |
| Entity Address, State or Province | IL |
| Entity Address, Postal Zip Code | 60606 |
| City Area Code | (312) |
| Local Phone Number | 416-8592 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common Stock |
| Trading Symbol | MAIA |
| Security Exchange Name | NYSEAMER |
| Entity Emerging Growth Company | true |
| Entity Ex Transition Period | false |
