The Malouin River is a tributary of the Harricana 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 movement is generally from mid-November to the end of April.

The main hydrographic slopes near the Malouin River are: The Malouin River originates from a forest stream (elevation: 264 metres (866 ft)), in the southern part of the municipality of Eeyou Istchee James Bay (municipality).

The designation "Malouin River" is indicated on a regional map of the Abitibi of the Department of Lands and Forests in 1962.

In 1895, explorer Henry O'Sullivan named this watercourse "Rivière du Mariage" (English: The River of Marriage) or "Birthday", having discovered him on September 15, 20th anniversary day of his marriage.