The Davoust River is a tributary of the northeast shore of the Nottaway River, flowing into the municipality of Eeyou Istchee Baie-James (municipality), in the administrative region of Nord-du-Québec, in Quebec, in Canada.

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

A forest road passes on the East side of Mouliers Lake.

The hydrographic slopes near the Davoust River are: The Davoust River has its source at the mouth of Lake Mouliers (length: 2.9 kilometres (1.8 mi), wide: 2.4 kilometres (1.5 mi); altitude: 244 metres (801 ft)).

From the mouth of Mouliers Lake, the Davoust River flows over 19.8 kilometres (12.3 mi) through the following segments: The mouth of the Davoust River is located at: The toponym "Davoust River" was formalized on December 5, 1968, at the Commission de toponymie du Quebec.