Buade Lake is a freshwater body of the unorganized territory of Lac-Ashuapmushuan, Quebec, in the western part of the Regional County Municipality (MRC) Le Domaine-du-Roy, in the administrative region of Saguenay-Lac-Saint-Jean, in the province of Quebec, in Canada. This lake straddles the townships of Buade and Poutrincourt. It is located west of the Ashuapmushuan Wildlife Reserve.