Castrillón, in Asturias, is part of the province of Asturias. The municipality covers about 55.7 km² and had 21,998 inhabitants on 1 January 2025.
Density, at about 395 inhabitants per km², is that of a populous urban area, with residential districts, services and businesses. Of the 29 municipalities in the province of Asturias with at least 5,000 inhabitants, it is number 7 by population.
As the crow flies it lies about 24 km north-west of Oviedo, the provincial capital. The nearest major city is A Coruña, about 195 km away.
Nearby, within a few dozen kilometres, are other destinations featured in our guides: Oviedo (24 km), Gijón (27 km).
Below you will find a map of neighbouring municipalities, the weather, places to stay in the area and a link to all the municipalities in the province of Asturias.