| Saint-Longis | |
| Commune Status: | Commune |
| Arrondissement: | Mamers |
| Canton: | Mamers |
| Insee: | 72295 |
| Postal Code: | 72600 |
| Mayor: | Léopold Monceaux[1] |
| Term: | 2020 - 2026 |
| Intercommunality: | Maine Saosnois |
| Coordinates: | 48.3553°N 0.3458°W |
| Elevation Min M: | 102 |
| Elevation Max M: | 188 |
| Area Km2: | 11.22 |
| Demonym: | Longonien, Longonienne |
Saint-Longis is a commune in the Sarthe department in the region of Pays de la Loire in north-western France.