Lake Charles is the fifth-most populous city in the U.S. state of Louisiana, and the parish seat of Calcasieu Parish, located on Lake Charles, Prien Lake, and the Calcasieu River. Founded in 1861 in Calcasieu Parish, it is a major industrial, cultural, and educational center in the southwest region of the state. As of the 2020 U.S. census, Lake Charles's population was 84,872.