Castel San Vincenzo is a comune (municipality) situated in the Province of Isernia within the Molise region of Italy. The town is located approximately 50 kilometres west of Campobasso and about 15 kilometres northwest of Isernia.
The territory of Castel San Vincenzo is home to several notable landmarks, including the Abbey of San Vincenzo al Volturno. Additionally, the area features an artificial lake that was constructed in the 1950s specifically for a hydroelectric plant.