Alfondeguilla is a municipality in Spain, located in the province of Castellón within the Valencian Community. It lies in the eastern part of the country, in the autonomous region of Valencia.
The town is one of the smaller municipalities of the province of Castellón, situated in the inland comarca of La Plana Baixa. Like much of the surrounding area, it sits in a landscape of hills and mountains typical of the interior of the Valencian Community.
As a Spanish municipality, Alfondeguilla is administered as a local entity within the province of Castellón, with its own municipal government. Its official status and administrative identity are defined by its recognition as a municipality within the Valencian Community.