| Lansac | |
| Commune Status: | Commune |
| Image Coat Of Arms: | Blason Lansac.svg |
| Arrondissement: | Blaye |
| Canton: | L'Estuaire |
| Insee: | 33228 |
| Postal Code: | 33710 |
| Mayor: | Éric Pouchard[1] |
| Term: | 2020 - 2026 |
| Intercommunality: | Grand Cubzaguais |
| Coordinates: | 45.0622°N -0.5408°W |
| Elevation M: | 69 |
| Elevation Min M: | 7 |
| Elevation Max M: | 68 |
| Area Km2: | 6 |
Lansac (in French pronounced as /lɑ̃sak/; Occitan (post 1500);: Lançac) is a commune in the Gironde department in Nouvelle-Aquitaine in southwestern France.