| Saint-Sébastien | |
| Arrondissement: | Grenoble |
| Canton: | Matheysine-Trièves |
| Commune: | Châtel-en-Trièves |
| Insee: | 38456 |
| Postal Code: | 38710 |
| Coordinates: | 44.8483°N 5.8°W |
| Elevation M: | 845 |
| Elevation Min M: | 579 |
| Elevation Max M: | 1931 |
| Area Km2: | 21 |
| Population: | 260 |
| Population Date: | 2019 |
| Population Footnotes: | [1] |
Saint-Sébastien (in French pronounced as /sɛ̃ sebastjɛ̃/) is a former commune in the Isère department in southeastern France. On 1 January 2017, it was merged into the new commune Châtel-en-Trièves.[2]