In 1682, La Salle recorded the presence of a village of Quinipissa peoples in the vicinity of modern-day Hahnville.

In the early 1800s, following the sale of Louisiana, the United States established the St. Charles Courthouse in the area and a small community grew up around it.

In February 1872, Thomas Sharpe began laying out a village near the courthouse, which he called Flaggville after district judge Othelle J. Flagg.

Around the same time, former governor Michael Hahn, who had a sugar plantation upriver from Flaggville, began dividing his land to found Hahnville.

[5][6][7] As of the 2020 United States census, there were 2,959 people, 1,354 households, and 897 families residing in the CDP.