Saint-Aignan (), also unofficially Saint-Aignan-sur-Cher (, literally Saint-Aignan on Cher) is a commune and town in the Loir-et-Cher department in the administrative region of Centre-Val de Loire, France.
Saint-Aignan is located on the river Cher, and is around 35 km (about 21,75 mi) south of Blois.
Saint-Aignan is known for its quiet nature, its gastronomic products, its castle and church and also its history. In the commune is located the ZooParc de Beauval.