| Sainte-Gemme-la-Plaine | |
| Commune Status: | Commune |
| Image Coat Of Arms: | Blason Sainte-Gemme-la-Plaine.svg |
| Arrondissement: | Fontenay-le-Comte |
| Canton: | Luçon |
| Insee: | 85216 |
| Postal Code: | 85400 |
| Mayor: | Pierre Careil[1] |
| Term: | 2020 - 2026 |
| Intercommunality: | Sud Vendée Littoral |
| Coordinates: | 46.485°N -1.1103°W |
| Elevation M: | 13 |
| Elevation Min M: | 0 |
| Elevation Max M: | 44 |
| Area Km2: | 35.52 |
Sainte-Gemme-la-Plaine (in French pronounced as /sɛ̃t ʒɛm la plɛn/) is a commune in the Vendée department in the Pays de la Loire region in western France.
Sainte-Gemme-la-Plaine has an oceanic climate (Köppen climate classification Cfb). The average annual temperature in Sainte-Gemme-la-Plaine is . The average annual rainfall is with October as the wettest month. The temperatures are highest on average in August, at around, and lowest in January, at around . The highest temperature ever recorded in Sainte-Gemme-la-Plaine was on 18 July 2022; the coldest temperature ever recorded was on 15 January 1985.