Bossier Parish is a parish located in the northwestern part of the U.S. state of Louisiana. At the 2020 census, the population was 128,746. The parish seat is Benton. The principal city is Bossier City, which is located east of the Red River and across from the larger city of Shreveport, the seat of Caddo Parish. The parish was formed in 1843 from the western portion of Claiborne Parish.