| Saint-Jean-devant-Possesse | |
| Commune Status: | Commune |
| Arrondissement: | Vitry-le-François |
| Canton: | Sermaize-les-Bains |
| Insee: | 51489 |
| Postal Code: | 51330 |
| Mayor: | Thierry Dausseur[1] |
| Term: | 2020 - 2026 |
| Intercommunality: | Côtes de Champagne et Val de Saulx |
| Coordinates: | 48.8722°N 4.7981°W |
| Area Km2: | 5.33 |
Saint-Jean-devant-Possesse (in French pronounced as /sɛ̃ ʒɑ̃ dəvɑ̃ pɔsɛs/, literally Saint-Jean before Possesse) is a commune in the Marne department in north-eastern France.