It crosses the municipalities of Saint-Léonard-d'Aston and Sainte-Perpétue, in the Nicolet-Yamaska Regional County Municipality (MRC), in the administrative region of Centre-du-Québec, in Quebec, in Canada.

The main neighboring hydrographic slopes of the Lafont River are: The Lafont River takes its source in an agricultural zone near the railway, at the limit of the municipalities of Saint-Léonard-d'Aston and Sainte-Perpétue.

The Lafont River flows in an agricultural zone on: The Lafont River empties on the north bank of the Nicolet Southwest River at 4.7 kilometres (2.9 mi) upstream of the bridge in the village of Sainte-Brigitte-des-Saults and at 2.5 kilometres (1.6 mi) downstream of the Mitchell hamlet railway bridge.

[1] The term "Lafond" or "Lafont" turns out to be a family name of French origin.

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