For Saint-Prosper in Chaudière-Appalaches, see Saint-Prosper, Chaudière-Appalaches, Quebec.Saint-Prosper-de-Champlain is a municipality of 516 people in the Les Chenaux Regional County Municipality, in Quebec, Canada. It is the smallest municipality in terms of population in the regional county.Before September 4, 2010, it was known simply as Saint-Prosper.