Castillonroy (Spanish: [kastiʎonˈroi]) or Castellonroi (Catalan: [kəstəˌʎonˈrɔj], locally: [kasteˌʎonˈrɔj]) is a municipality located in the province of Huesca, Aragon, Spain. According to the 2007 census (INE), the municipality has a population of 382 inhabitants.
It has two official names: Castillonroy and Castellonroi.
Coordinates: 41°53′N 0°31′E / 41.883°N 0.517°E / 41.883; 0.517