| Saint-Vivien-de-Monségur | |
| Commune Status: | Commune |
| Arrondissement: | Langon |
| Canton: | Le Réolais et Les Bastides |
| Insee: | 33491 |
| Postal Code: | 33580 |
| Mayor: | Philippe Moute[1] |
| Term: | 2020 - 2026 |
| Coordinates: | 44.6169°N 0.1078°W |
| Elevation M: | 96 |
| Elevation Min M: | 41 |
| Elevation Max M: | 131 |
| Area Km2: | 15.83 |
Saint-Vivien-de-Monségur (in French pronounced as /sɛ̃ vivjɛ̃ də mɔ̃seɡyʁ/, literally Saint-Vivien of Monségur; Occitan (post 1500);: Sent Vivian de Montsegur) is a commune in the Gironde department in Nouvelle-Aquitaine in southwestern France.