| Casalvieri | |
| Official Name: | Comune di Casalvieri |
| Coordinates: | 41.6333°N 56°W |
| Region: | Lazio |
| Province: | Frosinone (FR) |
| Frazioni: | Purgatorio, Roselli |
| Mayor: | Franco Moscone |
| Area Total Km2: | 27.27 |
| Population Footnotes: | [1] |
| Population Total: | 2383 |
| Population As Of: | 30 December 2020 |
| Population Demonym: | Casalvierani |
| Elevation M: | 380 |
| Saint: | St. Honorius |
| Day: | May 31 |
| Postal Code: | 03034 |
| Area Code: | 0776 |
Casalvieri (Campanian: Neapolitan: Casaluere) is a comune (municipality) in the Province of Frosinone in the Italian region Lazio, located about 110km (70miles) southeast of Rome and about 30km (20miles) east of Frosinone.
Casalvieri borders the following municipalities: Alvito, Arpino, Atina, Casalattico, Fontechiari, Vicalvi.