Montmorillon is a commune in the Vienne department, in the Nouvelle-Aquitaine region, in central-western France. The clay mineral montmorillonite (a silicate) was named after Montmorillon when it was discovered there in 1847.

It is one of the two subprefectures of the Vienne department and the capital of the canton of Montmorillon.

Montmorillon is well known for its macarons, and has a museum dedicated to it.