Caumont-sur-Orne (, literally Caumont on Orne) is a former commune in the Calvados department in the Normandy region in northwestern France. On 1 January 2016, it was merged into the new commune of Thury-Harcourt-le-Hom.
The former commune is part of the area known as Suisse Normande.
In 2017, the town had 77 residents.