The Rivière à l'Ours (English: Bear River) is a tributary of the rivière des Aulnaies, flowing on the northwest bank of the Saint Lawrence River, successively in the municipalities of Bégin and Saint-Ambroise, in the Fjord-du-Saguenay, in the region administrative Saguenay–Lac-Saint-Jean, in the Province of Quebec, in Canada.

Secondary forest roads serve the upper part of this slope.

The Bear River surface is usually frozen from late November to early April, however safe circulation on the ice is generally from mid-December to late March.

This mouth is located at: In his report on the township of Bégin in 1895, the land surveyor Jean Maltais, mentions "la rivière à l'Ours".

[5] The toponym of “Rivière à l'Ours” was formalized on April 8, 1975, at the Place Names Bank of the Commission de toponymie du Québec.