Rivière du Sud (Richelieu River tributary)

The Rivière du Sud (French pronunciation:, "River of the South") is a tributary of the Richelieu River, flowing successively in the municipalities of Saint-Alexandre, Saint-Sébastien, Clarenceville and Henryville, in the Le Haut-Richelieu Regional County Municipality, in Montérégie, on the south shore of Fleuve Saint-Laurent, in province of Quebec, in Canada.

Agriculture is the main economic activity in this small valley; forestry, second in the lower part of the river.

The river surface is generally frozen from mid-December to the end of March. Safe traffic on the ice is generally from late December to early March. The water level of the river varies with the seasons and the precipitation.