| Trois Saumons River | |
| Pushpin Map: | Quebec |
| Subdivision Type1: | Country |
| Subdivision Name1: | Canada |
| Subdivision Type2: | Province |
| Subdivision Name2: | Quebec |
| Subdivision Type3: | Region |
| Subdivision Name3: | Chaudière-Appalaches |
| Subdivision Type4: | MRC |
| Subdivision Name4: | L'Islet Regional County Municipality |
| Source1: | Lake Trois Saumons |
| Source1 Location: | Saint-Aubert |
| Mouth: | St. Lawrence River |
| Mouth Location: | L'Islet |
| Basin Size: | NaNkm (-2,147,483,648miles) |
| Tributaries Left: | (upstream) |
| Tributaries Right: | (upstream) |
The Trois Saumons River (in French: Rivière Trois Saumons) is a tributary of the south shore of the St. Lawrence River where it flows to the southwest of the village of Saint-Jean-Port-Joli and to the north-east of the village of L'Islet-sur-Mer. The Trois-Saumons river water mill in Saint-Jean-Port-Joli is located upstream of route 132.
The Trois Saumons River flows through the municipalities of Saint-Aubert and Saint-Jean-Port-Joli, in the L'Islet Regional County Municipality, in the administrative region of Chaudière-Appalaches, in Quebec, in Canada.
The Trois Saumons river takes its source from Trois Saumons lake (length: ; altitude:), located in the municipality of Saint-Aubert. This recreational and tourist-oriented lake, with a significant density of chalets on its banks, is surrounded by forest. This head lake is located southeast of the south shore of the St. Lawrence River, south of the center of the village of Saint-Aubert and at northeast of the village center of Saint-Cyrille-de-Lessard. Trois Saumons Lake flows through its northeast end.
From its source, the Trois Saumons River flows over, divided into the following segments:
At the end of its course, the Trois Saumons River flows onto the long shore (at low tide) in the Anse de Trois-Saumons, on the south shore of the middle estuary of the St. Laurent. This confluence is located north-east of the village of L'Islet-sur-Mer and to the south-west of the village of Saint-Jean-Port-Joli.[1]
The toponym Rivière Trois Saumons was formalized on December 5, 1968, at the Commission de toponymie du Québec.[2]