The Rivière aux Bluets Sud (in English: Blueberries South River) is a tributary of the rivière aux Bluets which flows on the east shore of Grand lac Saint François; the latter constitutes the head lake of the Saint-François River.

The course of the "Rivière aux Bluets Sud" crosses the territory of the municipalities of Saint-Sébastien and Courcelles-Saint-Évariste, in the Le Granit Regional County Municipality, in the administrative region of Estrie, on the South Shore of the St. Lawrence River, in Quebec, Canada.

The main hydrographic slopes close to the "Rivière aux Bluets Sud" are: The "Rivière aux Bluets Sud" has its source on the northern slope of the "Morne de Saint-Sébastien" at 1.2 kilometres (0.75 mi) from the summit which reaches 805 metres (2,641 ft).

From its source, the river flows over: The mouth of the "rivière aux Bleuts Sud" empties on the south shore of the rivière aux Bluets (Grand lac Saint François), which flows north-west to flow onto the east bank of the Grand lac Saint François.

[2] The toponym "Rivière aux Bluets Sud" was officially registered on December 5, 1968, at the Commission de toponymie du Québec.