The latter was ordained in 1830 and occupied the post of Chancellor of the Bishop of Montreal, Mgr Ignace Bourget, during the creation of the canonical erection of the parish, in 1851.

[5] The parish of Saint-Alexis was created on July 1, 1855, after the dissolution of the county of Leinster (witch covered the territory approximately equivalent to the RCMs of Montcalm, Les Moulins and L'Assomption) in the highlands of the plain of Saint -Laurent, about twenty kilometres north of Saint-Roch-de-l'Achigan, in the Lanaudière region.

The chosen name, Saint-Alexis, also attributed to the post office established in 1855, which took the name of "Saint-Alexis-de-Montcalm" in 1876, pays homage to Canon Alexis-Frédéric Truteau (1808-1872).

the two major roads are called Grande-Ligne and Petite-Ligne and houses a number of ancestral homes that were built facing south, a local characteristic.

There are also farms producing pork, dairy, poultry and maple syrup production accompanied by its commercial sugar shack.