| Saint-Cassien | |
| Commune Status: | Commune |
| Arrondissement: | Bergerac |
| Canton: | Lalinde |
| Insee: | 24384 |
| Postal Code: | 24540 |
| Mayor: | Philippe Poumeau[1] |
| Term: | 2020 - 2026 |
| Coordinates: | 44.6867°N 0.8461°W |
| Elevation M: | 175 |
| Elevation Min M: | 120 |
| Elevation Max M: | 225 |
| Area Km2: | 4.72 |
Saint-Cassien (in French pronounced as /sɛ̃ kasjɛ̃/; Occitan (post 1500);: Sent Cassian) is a commune in the Dordogne department in Nouvelle-Aquitaine in southwestern France.