Saint-Perreux (French pronunciation: [sɛ̃ pɛʁø] ⓘ; Breton: Sant-Pereg) is a commune in the Morbihan department of Brittany in north-western France.

[3] It was named after the Welsh monk, Saint Petroc.

The river Arz forms most of the commune's western and south-western borders, then flows (at Saint-Jean-la-Poterie) into the Oust, which forms the commune's eastern border.

Inhabitants of Saint-Perreux are called in French Perrusiens or Perreusiens.

This Morbihan geographical article is a stub.