Saint-Ouen-des-Alleux (French pronunciation: [sɛ̃.t‿wɛ̃ de.z‿alø]; Breton: Sant-Owen-an-Alloz) is a commune in the Ille-et-Vilaine department in Brittany in northwestern France.

Saint-Ouen-des-Alleux is located 34 km (21 mi) northeast of Rennes and 38 km (24 mi) south of Mont Saint-Michel.

The adjacent communes are Saint-Christophe-de-Valains, Le Tiercent, Saint-Hilaire-des-Landes, Saint-Marc-sur-Couesnon, Mézières-sur-Couesnon, and Vieux-Vy-sur-Couesnon.

Inhabitants of Saint-Ouen-des-Alleux are called audonniens in French.

This Ille-et-Vilaine geographical article is a stub.