The Caupichigau River is a tributary of the La Trève River, flowing into Regional County Municipality (RCM) of Eeyou Istchee James Bay (municipality), within the administrative region of Nord-du-Québec, Canadian province of Quebec, in Canada.

The hydrographic slope of the Caupichigau River is accessible on road 113 linking Lebel-sur-Quévillon to Chibougamau.

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

The current flows westward to the east shore of Maicasagi Lake.

The mouth of the Caupichigau River located at: The toponym "Caupichigau River" was formalized on December 5, 1968, at the Commission de toponymie du Québec, which created this commission[3] Download coordinates as: