The rivière du Petit Sault (English: Small Sault river) flows through the municipalities of Saint-Éloi (MRC Les Basques Regional County Municipality) and L'Isle-Verte (MRC of Rivière-du-Loup Regional County Municipality), in the administrative region of Bas-Saint-Laurent, in Quebec, in Canada.

The Petit Sault river takes its source from agricultural streams located in the municipality of Saint-Éloi.

This source is located at 6.1 km (3.8 mi) to the southeast of the southeast coast of the estuary of Saint Lawrence, at 1.0 km (0.62 mi) to the southwest from a bend in the Trois Pistoles River and at 3.5 km (2.2 mi) northeast of the center of the village of Saint-Éloi .

From its source, the Petits Saults river flows in an agricultural zone over 12.2 km (7.6 mi) according to the following segments: The Petit Sault river flows into Anse Verte, on the Loups Marins flats, of the St. Lawrence River, in the village of the municipality of L'Isle-Verte, facing the Île aux Pommes, located 5.1 km (3.2 mi) from the shore.

This confluence is located 6.1 km (3.8 mi) northeast of the center of the village of L'Isle-Verte.