Napoleonville is a village in and the parish seat of Assumption Parish, in the U.S. state of Louisiana. The population was 686 at the 2000 census. It is part of the Pierre Part Micropolitan Statistical Area.
As early as 1807 the community that later became Napoleonville was known as "Canal." This canal extended west from Napoleonville to Lake Verret. The town was named by a soldier who served under Napoleon Bonaparte.
The first permanent settlements in this region were made by the French and Spanish (including Islenos) about the middle of the 18th century along Bayou Lafourche, between the present towns of Donaldsonville and Napoleonville. From 1755 to 1764, the population was increased by the immigration of the exiled Acadians who entered the area clearing the land and building comfortable homes. The town was officially incorporated on March 11, 1878.