Cangas de Onís (Asturian: Cangues d'Onís) is a municipality in the eastern part of the province and autonomous community of Asturias in the northwest of Spain. The capital of the municipality is also Cangas de Onís.
More than seventy square kilometres of the concejo form part of the Parque nacional de los Picos de Europa. Within the park is the village of Covadonga, where the battle of Covadonga (about 722), the first major victory by a Christian military force in Iberia after the Islamic conquest, marks the starting-point of the Reconquista.
Until 774, Cangas de Onís was the capital of the Kingdom of Asturias. It was the site of the first church constructed in post-conquest Iberia, Santa Cruz de Cangas de Onís (737), built on an ancient dolmen.