Prairieville is a census-designated place in Ascension Parish, Louisiana, United States. It is south of Baton Rouge and north of Gonzales. Prairieville is an expanding bedroom suburb of Baton Rouge. Its name is derived from the once plentiful pastures and prairies that were visible from Highway 73 and Airline Highway, which is now covered with development. Prairieville started off as a quiet community with few people.