Aunou-sur-Orne (, literally Aunou on Orne) is a commune in the Orne department in northwestern France.
Aunou-sur-Orne along with another 65 communes is part of a 20,593 hectare, Natura 2000 conservation area, called the Haute vallée de l'Orne et affluents.
In 1811 Aunou-sur-Orne absorbed the neighbouring commune of Saint-Cenery-près-Séez (sometimes spelled Saint-Cénery-près-Sées or Saint-Céneri-près-Sées).
The commune contains the source of the river Orne.
Nicolas-Jacques Conté (4 August 1755 â 6 December 1805) was a French painter, balloonist, army officer, and inventor of the modern pencil. He was born at Saint-Céneri-près-Sées.