Winn Parish is a parish located in the U.S. state of Louisiana. As of the 2020 census, the population was 13,755. Its seat and largest city is Winnfield. The parish was founded in 1852. It is last in alphabetical order of Louisiana's sixty-four parishes. Winn is separated from Natchitoches Parish along U.S. Highway 71 by Saline Bayou, the first blackwater protected waterway in the American South.

Winnfield is a small city in, and the parish seat of, Winn Parish, Louisiana, United States. The population was 5,749 at the 2000 census, and 4,840 in 2010. Three governors of the state of Louisiana were from Winnfield: Huey Long, Earl K. Long, and Oscar K. Allen.