Maskoskanaw River is a tributary of Frontenac Lake (Milieu River), flowing into the unorganized territory of Lac-Ashuapmushuan, Quebec, in the Regional County Municipality (MRC) of Le Domaine-du-Roy, in the administrative region of Saguenay-Lac-Saint-Jean, in Quebec, in Canada.

The Maskoskanaw River flows successively into the townships of Huard and Buade.

The surface of the Maskoskanaw River is usually frozen from early November to mid-May, however, safe ice movement is generally from mid-November to mid-April.

The Maskoskanaw River originates at the mouth of the Malsain Lake (length: 0.9 kilometres (0.56 mi); width: 0.2 kilometres (0.12 mi); altitude: 502 metres (1,647 ft)) located in Huard Township.

The toponym "Maskoskanaw River" was formalized on September 6, 1984, at the Commission de toponymie du Québec.