Plouguin (French pronunciation: [pluɡɛ̃]; Breton: Plougin) is a commune in the Finistère department of Brittany in north-western France.

It lies 20 km (12 mi) northwest of Brest, about 7 km (4.3 mi) from the English Channel in the far west of the Leon peninsula.

Inhabitants of Plouguin are called in French Plouguinois.

Plouguin is considered to have been (about 460) the birthplace of Saint Winwaloe, and his supposed place of birth, a feudal hillock, is still pointed out.

Plouguin is twinned with the town of Newport in Pembrokeshire, Wales.