The Beaudet river flows in the municipalities of Sainte-Marie-de-Blandford, located in the Bécancour Regional County Municipality), in the region administrative office of Centre-du-Québec, in Quebec, in Canada.

The main neighboring hydrographic slopes of the Beaudet River are: The Beaudet River rises at the limit of the municipalities of Lemieux and Sainte-Marie-de-Blandford.

This head area is located in the southern part of Sainte-Marie-de-Blandford 3.2 kilometres (2.0 mi) east of the village, 3.1 kilometres (1.9 mi) northwest of the village center of Lemieux and 11.6 kilometres (7.2 mi) south of the village of Sainte-Sophie-de-Lévrard.

Its confluence is located 3.7 km northeast of the center of the village of Sainte-Gertrude and 4.5 kilometres (2.8 mi) west of the village of Sainte-Marie-de-Blandford.

The toponym "rivière Baudet" was made official on August 17, 1978, at the Commission de toponymie du Québec.