The rivière aux Iroquois (French pronunciation: [ʁivjɛʁ oz‿iʁɔkwa]) is a tributary of lac Saint-Jean, flowing the municipality of Sainte-Hedwidge and Saint-Prime, in the Le Domaine-du-Roy Regional County Municipality, in the administrative region of Saguenay–Lac-Saint-Jean, in the province of Quebec, in Canada.

[2] The surface of the Iroquois River is usually frozen from the beginning of December to the end of March, except the rapids areas; however, traffic on the ice is generally safe from mid-December to mid-March.

This deformed lake has two parts separated by a peninsula which face each other: one of 0.6 km (0.37 mi) attached to the north shore and the other of 0.13 km (0.081 mi), attached to the south shore.

This confluence is located between the villages of Saint-Prime and Pointe-Bleue, either: From the mouth of the Iroquois River, the current crosses Lake Saint-Jean east on 42.5 km (26.4 mi) northeast, follows the course of the Saguenay River (via the Little Landfill) on 172.3 km (107.1 mi) eastwards to Tadoussac where it merges with the Estuary of Saint Lawrence.

The toponym "Rivière aux Iroquois" was formalized on December 5, 1968, at the Place Names Bank of the Commission de toponymie du Québec.