The Lac Desprez is a fresh body of water in the watershed of ruisseau à John and Malbaie River.

The surface of the Rivière des Cèdres is usually frozen from the beginning of December to the end of March, however the safe circulation on the ice is generally made from mid-December to mid-March.

Lac Desprez is located about 4.8 km (3.0 mi) north of the boundary of the administrative regions of Saguenay-Lac-Saint-Jean and Capitale-Nationale.

Its mouth is located to the northwest, at: north of the center of the village of Ferland in the municipality of Ferland-et-Boilleau; From the mouth of Lac Desprez, the current: The term "Desprez" constitutes a family name designating a place of provenance: "the meadows", itself coming from Latin "pratum".

The toponym "Lac Desprez" was formalized on December 12, 1985, by the Commission de toponymie du Québec.