The Loutre River is a tributary of the northwest shore of the St. Lawrence River, flowing into the town of La Malbaie, between the towns of Cap-à-l'Aigle and Saint-Fidèle, in the Charlevoix-Est Regional County Municipality, in the administrative region of Capitale-Nationale, in Quebec, in Canada. The course of this river flows into the St. Lawrence in the hamlet of Bas-de-l'Anse, northeast of the town of La Malbaie.

The valley of this watercourse is served by route 138 (Malcolm-Fraser Blvd.) which runs along the northwest shore of the St. Lawrence River and by route Sainte-Mathilde East.

Forestry is the main economic activity of the sector; recreational tourism activities (including resort and bed and breakfasts), second.

The surface of this stream is generally frozen from mid-December to late-March. Nevertheless, safe ice traffic is generally from late December to mid-March.

The main hydrographic slopes near the "Loutre River" are:

• North side: Port au Persil River, Noire River, Port au Saumon River, Saguenay River;
• East side: St. Lawrence River;
• South side: St. Lawrence River;
• West side: Baptiste-Jean brook, Comporté River, Jacob River, Snigole River, Malbaie River.

The Loutre River originates from a small unidentified lake (length: 0.2 km (0.12 mi); altitude: 317 m (1,040 ft)) in forest area. From the mouth of this head lake, the course of the Loutre River descends by traveling 5.8 km (3.6 mi) according to the following segments:

• 1.0 km (0.62 mi) south by cutting a forest road to a bend in the river, corresponding to the confluence of a creek (coming from the east);
• 2.4 km (1.5 mi) south to a creek (coming from the east);
• 1.0 km (0.62 mi) southerly, bypassing the hamlet of Bas-de-Anse, to the bridge of route 138;
• 1.4 km (0.87 mi) southeasterly down the cliff in a forest area to the shore of the Gulf of St. Lawrence.

The origin of the name "rivière à la Loutre" is related to the presence of otters in this area.

The toponym "rivière à la Loutre" was formalized on December 5, 1968 at the Bank of place names of the Commission de toponymie du Quebec.

• List of rivers of Quebec