The Petite rivière aux Saumons (English: Little Salmons River) is a tributary of the Ashuapmushuan River, flowing in the unorganized territory of Rivière-Mistassini and in the municipality of Saint-Thomas-Didyme, in the Maria-Chapdelaine Regional County Municipality, in the administrative region of Saguenay–Lac-Saint-Jean, in the province of Quebec, in Canada.

The valley of the Petite rivière aux Saumons is mainly served by forest roads.

[1] The Petite rivière aux Saumons has its source at the mouth of the lake Anita (length: 0.34 km (0.21 mi); altitude: 279 m (915 ft)).

The mouth of the lake Anita is located in a forest zone in the unorganized territory of Rivière-Mistassini, at: From the mouth of the lake Anita, the Petite rivière aux Saumons flows over 13.1 km (8.1 mi), with a drop of 83 m (272 ft), entirely in a forest area, according to the following segments: The Petite rivière aux Saumons empties on the north bank of the Ashuapmushuan River at 4.0 km (2.5 mi) upstream from the confluence of the rivière à la Loutre.

The toponym "Petite rivière aux Saumons" was made official on September 29, 1975, at the Place Names Bank of the Commission de toponymie du Québec.