Mamousia (Greek: Μαμουσιά) is a village and a community in the municipal unit of Diakopto, Achaea, Greece.

It is 6 km southwest of Diakopto, on the west side of the Vouraikos gorge.

The ancient city Boura was located near present Mamousia.

The city had an ancient theatre most of which has yet to be excavated; several artifacts are on display at the Aigio Archeological Museum.

Mamousia suffered damage from the 2007 Greek forest fires.