Damville Lake is a freshwater body of the Rivière-Mistassini, unorganized territory of the Maria-Chapdelaine Regional County Municipality, north-west of Saguenay-Lac-Saint-Jean administrative region, in province of Quebec, Canada.

A peninsula attached to the east bank stretches for 1.1 km (0.68 mi) to the northwest.

The mouth of Lake Damville is located at: The main hydrographic slopes near Lake Damville are: From the mouth of Damville Lake (located at the bottom of the north-west bay of the lake), the current crosses an extension of 1.8 km (1.1 mi) of the lake; then descends the course of the rivière aux Brochets on 0.9 km (0.56 mi) toward south-west; descends the Ashuapmushuan River on 100.4 km (62.4 mi), the current crosses Lac Saint-Jean east on 41.1 km (25.5 mi) (its full length), follows the course of the Saguenay River via the Petite Décharge on 172.3 km (107.1 mi) east to Tadoussac where it merges with the Estuary of Saint Lawrence.

[1] The term "Damville" refers to an old French commune in the Eure department in the Normandy region.

The toponym "Lac Ashuapmushuan" was formalized on June 18, 1993, by the Commission de toponymie du Québec.