Chahains () is a commune in the Orne department in north-western France.
The commune is made up of the following collection of villages and hamlets, Le Jardin and Chahains.
It is in size. The highest point in the commune is .
The commune is within the Normandie-Maine Regional Natural Park and Forêt d'ÃÂcouves.
The River Udon and 3 streams, the Grand Pied, the Moulin de Besnard and the Coupigny are the four watercourses that flow through this commune. The source of the river Udon is in this commune.