Castelnuovo di Farfa is a comune, or municipality, situated in the Province of Rieti within the Italian region of Latium. It is located approximately 40 kilometres northeast of Rome and about 20 kilometres southwest of the city of Rieti.
The town serves as a local administrative center in the rural landscape of central Italy. Its geographical position places it within the historical territory of the Rieti province, characterized by its proximity to major regional hubs.