Saint-Cyr-du-Bailleul () is a commune in the Manche department in Normandy in northwestern France.
The commune is made up of the following collection of villages and hamlets, La Gravengerie, Le Jarry, Saint-Cyr-du-Bailleul, Launay, La Ruaudière, Mongodin and L'hôtel aux Piels.
The source of the river Sélune is in this commune.
The commune is in the Normandie-Maine Regional Natural Park.