Marianna is a town in and the county seat of Lee County, Arkansas, United States. As of the 2010 census it had a population of 4,115, but by 2018 the population had dropped to an estimated 3,477. Located along the L'Anguille River in the Arkansas Delta just north of the St. Francis National Forest, the community was known as "Walnut Ridge" until 1852 when it became known as "Marianna". The town's economy has historically been based on agriculture, especially cotton production.