The Beaudet River (in French: rivière Beaudet) is a tributary of the Gentilly River which flows onto the south shore of the St. Lawrence River.
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 east of the village, northwest of the village center of Lemieux and south of the village of Sainte-Sophie-de-Lévrard.
From its head zone, the Beaudet River flows over with a drop of , divided into the following segments:
The Beaudet River empties on the west bank of the Gentilly River. Its confluence is located 3.7 km northeast of the center of the village of Sainte-Gertrude and 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.