Saint-Léonard (French pronunciation: [sɛ̃ leɔnaʁ] ⓘ) is a former town in Madawaska County, New Brunswick, Canada.

Saint-Léonard was once a popular town during Prohibition in the United States as it was easy to smuggle alcohol to Van Buren.

On June 30, 2008, a truck carrying 12 million bees overturned near Saint-Léonard.

[3] On 1 January 2023, Saint-Léonard amalgamated with the village of Sainte-Anne-de-Madawaska and parts of four local service districts to form the new town of Vallée-des-Rivières.

The town has a warm-summer humid continental climate (Köppen: Dfb), even for this type of climate the warm season can be milder for a non-coastal city like Saint John, because the Great Lakes and Appalachians hold much of the heat.