| Saint-Martin-du-Tertre | |
| Commune Status: | Commune |
| Image Coat Of Arms: | Blason de la ville de Saint-Martin-du-Tertre (Yonne).svg |
| Coordinates: | 48.2144°N 3.26°W |
| Insee: | 89354 |
| Postal Code: | 89100 |
| Arrondissement: | Sens |
| Canton: | Sens-1 |
| Mayor: | Daniel Cordillot[1] |
| Term: | 2020 - 2026 |
| Intercommunality: | CA Grand Sénonais |
| Elevation Min M: | 62 |
| Elevation Max M: | 183 |
| Area Km2: | 6.91 |
Saint-Martin-du-Tertre (in French pronounced as /sɛ̃ maʁtɛ̃ dy tɛʁtʁ/) is a commune in the Yonne department in Bourgogne-Franche-Comté in north-central France. It is situated on the left bank of the river Yonne, 2 km northwest of Sens.