The river originates in the Otish Mountains, and flows in a southerly direction for its entire course.

It drains into Outardes Bay of the Saint Lawrence River, about 20 kilometers (12 mi) southwest of Baie-Comeau.

At its mouth, the Outardes River widens and flows over a sandbar, making it extremely shallow.

There are several islands in Outardes Bay of which the most notable are White Island (île Blanche), a rock of white granite 23 meters (75 ft) high, and Mine Island (île de la Mine), a bare red rock reaching 15 meters (49 ft) high.

[2] Among its significant tributaries are: The river has been developed for hydro-electric power generation as part of the Manic-Outardes Project in the 1960s and 1970s.