| Montdidier | |
| Commune Status: | Commune |
| Image Coat Of Arms: | Blason ville fr Montdidier 57.svg |
| Arrondissement: | Sarrebourg-Château-Salins |
| Canton: | Le Saulnois |
| Insee: | 57478 |
| Postal Code: | 57670 |
| Mayor: | Jean Pfeiffer[1] |
| Term: | 2020 - 2026 |
| Intercommunality: | CC du Saulnois |
| Coordinates: | 48.9303°N 6.8181°W |
| Elevation M: | 306 |
| Elevation Min M: | 234 |
| Elevation Max M: | 307 |
| Area Km2: | 1.93 |
Montdidier (in French pronounced as /mɔ̃didje/; German: Diedersberg) is a commune in the Moselle department in Grand Est in north-eastern France.