This small river of about 40 kilometres (25 mi) in length flows in the municipalities of Saint-Charles-de-Bellechasse, Saint-Michel-de-Bellechasse and Saint-Vallier, in the Bellechasse Regional County Municipality, in the administrative region of Chaudière-Appalaches, in Quebec, in Canada.

Apart from a few forest areas crossed by the river, agriculture is the main economic activity in this valley.

The water level of the river varies with the seasons and the precipitation; the spring flood occurs in March or April.

[3] This source is located in range Nord-Ouest 4.8 km south-west of the center of the village of Saint-Charles-de-Bellechasse, south-east of Plée de Saint-Charles and 1, 3 km northeast of the limit of Saint-Henri.

Its main tributaries are: The toponym "rivière Boyer" was officialized on December 5, 1968, at the Commission de toponymie du Québec.