Châteauneuf-du-Faou is a commune in the Finistère department of Brittany in north-western France.
Châteauneuf-du-Faou is located in the middle of Brittany, between Monts d'Arrée and Montagne Noire. The town is built on a hill overlooking the Canal de Nantes à Brest, which is the canalized river Aulne. The bridge over this waterway was built in 1638, when Louis XIII was king of France, and is known as the "Old King's Bridge".