| Gentilly South-West River | |
| Pushpin Map: | Quebec |
| Subdivision Type1: | Country |
| Subdivision Name1: | Canada |
| Subdivision Type2: | Province |
| Subdivision Name2: | Quebec |
| Subdivision Type3: | Region |
| Subdivision Name3: | Centre-du-Québec |
| Subdivision Type4: | MRC |
| Subdivision Name4: | Bécancour Regional County Municipality |
| Source1: | Agricultural streams |
| Mouth: | Gentilly River (Quebec) |
| River System: | Gentilly River (Quebec), St. Lawrence River |
| Tributaries Left: | (upstream) rivière de Grand-Saint-Louis, ruisseau Deshaies-Cormier, ruisseau Alphonse, ruisseau Alphonse-Deshaies. |
| Tributaries Right: | (upstream) ruisseau Leblanc, cours d'eau Ernest-Provencher, ruisseau Oscar-Provencher, ruisseau Désilets, ruisseau David-Lacourse, ruisseau Émilien-Leblanc. |
The Gentilly South-West River (in French: rivière Gentilly Sud-Ouest) is a tributary of the Gentilly River which flows on the south shore of the St. Lawrence River.
The Gentilly Sud-Ouest river flows in the territory of the municipality of Saint-Sylvère and the town of Bécancour, in the MRC of Bécancour Regional County Municipality, in the administrative region of Centre-du-Québec, in Québec, in Canada.
The main neighboring hydrographic slopes of the Gentilly Sud-Ouest river are:
The Gentilly Sud-Ouest river draws its source in an agricultural zone, from the confluence of two streams, in the eighth rang of Saint-Sylvère. This area is located north of the Bécancour River, southwest of the village of Saint-Sylvère and northeast of the village of Saint-Wenceslas.
From its head area, the Gentilly Sud-Ouest River flows with a drop of over in the following segments:
The Sud-Ouest Gentilly River flows onto the west bank of the Gentilly River, in Bécancour.
The toponym “rivière Gentilly Sud-Ouest” was made official on December 5, 1968, at the Commission de toponymie du Québec.[2]