| Montmirail | |
| Commune Status: | Commune |
| Arrondissement: | Épernay |
| Canton: | Sézanne-Brie et Champagne |
| Insee: | 51380 |
| Postal Code: | 51210 |
| Mayor: | Etienne Dhuicq[1] |
| Term: | 2020 - 2026 |
| Intercommunality: | CC Brie Champenoise |
| Coordinates: | 48.8702°N 3.5371°W |
| Elevation M: | 205 |
| Area Km2: | 48.82 |
Montmirail (pronounced as /fr/) is a commune in the Marne department in north-eastern France.thumb|left|Castle, church
Jean François Paul de Gondi, cardinal de Retz (1613-1679), a French churchman, writer of memoirs, and agitator in the Fronde was born in Montmirail.[2]