| Saint-Mars-Vieux-Maisons | |
| Commune Status: | Commune |
| Coordinates: | 48.7425°N 3.3211°W |
| Insee: | 77421 |
| Postal Code: | 77320 |
| Arrondissement: | Provins |
| Canton: | Coulommiers |
| Mayor: | Patrick Pettinger[1] |
| Term: | 2020 - 2026 |
| Elevation Min M: | 130 |
| Elevation Max M: | 183 |
| Area Km2: | 19.02 |
Saint-Mars-Vieux-Maisons (in French pronounced as /sɛ̃ maʁ vjø mɛzɔ̃/) is a commune in the Seine-et-Marne department in the Île-de-France region in north-central France.