The rivière Saint-Charles is a tributary of the south shore of the Saint Lawrence River, flowing in the city of Varennes, in the Marguerite-D'Youville Regional County Municipality, in the administrative region of Montérégie, southwest of province of Quebec, to Canada.

The lower course of the Saint-Charles river more or less delimits the urban part of Varennes passing on the south side.

Safe circulation on the ice is generally done from the end of December to the beginning of March.

The main hydrographic slopes neighboring the Saint-Charles River are: The Rivière aux Pins rises at the mouth of a small lake (length: 0.35 kilometres (0.22 mi); altitude: 31 metres (102 ft)) set up in the heart of a golf course.

This river flows over 13.9 kilometres (8.6 mi), with a drop of 24 metres (79 ft), according to the following segments: The mouth of the Saint-Charles river is located on the southeast bank of the Saint Lawrence River heart of the city of Varennes, opposite Île Sainte-Thérèse, either: The toponym "Rivière aux Pins" was formalized on December 5, 1968, at the Commission de toponymie du Québec.