Estopiñán del Castillo (Spanish: [estopiˈɲan del kasˈtiʎo]), in Ribagorçan: Estopanyà[2] (Catalan: [astopaˈɲa]; in Aragonese: Estupinyán) is a municipality located in the province of Huesca, Aragon, Spain. According to the 2004 census (INE), the municipality had a population of 217 inhabitants.
In this municipality, the inhabitants speaks a variety transition of Catalan and Aragonese languages, called Ribagorçan.
41°59′42″N 0°32′31″E / 41.995°N 0.542°E / 41.995; 0.542