| Sermamagny | |
| Commune Status: | Commune |
| Image Coat Of Arms: | Blason ville fr Sermamagny (Territoire de Belfort).svg |
| Coordinates: | 47.6922°N 6.8358°W |
| Insee: | 90093 |
| Postal Code: | 90300 |
| Arrondissement: | Belfort |
| Canton: | Valdoie |
| Mayor: | Philippe Challant[1] |
| Term: | 2020 - 2026 |
| Intercommunality: | Grand Belfort |
| Elevation Min M: | 384 |
| Elevation Max M: | 423 |
| Area Km2: | 7.90 |
Sermamagny (in French pronounced as /sɛʁmamaɲi/) is a commune in the Territoire de Belfort department in Bourgogne-Franche-Comté in northeastern France.