Rohault Lake is a freshwater body of the unorganized territory of Lac-Ashuapmushuan, Quebec, in the western part of Le Domaine-du-Roy, in the administrative region of Saguenay-Lac-Saint-Jean, in province of Quebec, in Canada. This lake extends into the townships of Rohault, Robert and Ducharme (near the mouth). Forestry is the main economic activity of the sector. Recreational tourism activities come second. The surface of lake Rohault is usually frozen from early November to mid-May, however, safe ice circulation is generally from mid-November to mid-April.