| Messapia | |
| Name Local: | Μεσσάπια |
| Type: | municipal unit |
| Coordinates: | 38.5833°N 62°W |
| Periph: | Central Greece |
| Periphunit: | Euboea |
| Municipality: | Dirfys-Messapia |
| Population As Of: | 2021 |
| Pop Municunit: | 12048 |
| Area Municunit: | 433.26 |
| Licence: | ΧΑ |
Messapia (Greek, Modern (1453-);: Μεσσάπια) is a former municipality in Euboea, Greece. Since the 2011 local government reform, it is part of the Dirfys-Messapia municipality, of which it is a municipal unit.[1] The municipal unit has an area of 433.26 km2[2] and a population of 12,048 (2021). Its name derives from the ancient river Messapios, which flows through the middle of the island. The seat of the municipality was in Psachna.