| Belmonte del Sannio | |
| Official Name: | Comune di Belmonte del Sannio |
| Coordinates: | 41.8167°N 39°W |
| Region: | Molise |
| Province: | Isernia (IS) |
| Mayor: | Errico Borrelli |
| Area Total Km2: | 20.32 |
| Population Footnotes: | [1] |
| Population Total: | 735 |
| Population As Of: | 31 December 2017 |
| Population Demonym: | Belmontesi |
| Elevation M: | 864 |
| Postal Code: | 86080 |
| Area Code: | 0865 |
Belmonte del Sannio is a comune (municipality) in the Province of Isernia in the Italian region Molise, located about 35km (22miles) northwest of Campobasso and about 30km (20miles) northeast of Isernia.
Belmonte del Sannio borders the following municipalities: Agnone, Castiglione Messer Marino, Schiavi di Abruzzo.