Saint-Antonin is a city in the Bas-Saint-Laurent region of Quebec, Canada, a few kilometres south of the city of Rivière-du-Loup, in Rivière-du-Lo…Saint-Antonin is a city in the Bas-Saint-Laurent region of Quebec, Canada, a few kilometres south of the city of Rivière-du-Loup, in Rivière-du-Loup Regional County Municipality. The municipality is named after Louis-Antonin or Antoine Proulx, priest of Fraserville and was founded in 1856.