| San Gemini | |
| Official Name: | Comune di San Gemini |
| Coordinates: | 42.6111°N 12.5458°W |
| Region: | Umbria |
| Province: | Terni (TR) |
| Frazioni: | Acquavogliera, Colle Pizzuto, Quadrelletto, Sangemini Fonte |
| Mayor: | Luciano Clementella |
| Area Total Km2: | 27.9 |
| Population Footnotes: | [1] |
| Population Total: | 5015 |
| Population As Of: | 30 June 2016 |
| Population Demonym: | Sangeminesi |
| Elevation M: | 337 |
| Saint: | San Gemine |
| Day: | 9 October |
| Postal Code: | 05029 |
| Area Code: | 0744 |
San Gemini is a comune (municipality) of c. 5,000 inhabitants in the province of Terni in the Italian region Umbria, located about 60 km south of Perugia and about 10 km northwest of Terni.
San Gemini borders the municipalities of Montecastrilli, Narni and Terni. It is one of I Borghi più belli d'Italia ("The most beautiful villages of Italy").[2]
The town is a well-preserved medieval burgh with two lines of walls, built over the remains of a small Roman center along the old Via Flaminia. It is especially known for its mineral waters.