Benton is a home rule-class city and the county seat of Marshall County, Kentucky, United States. The current mayor of this city is Rita Dotson…Benton is a home rule-class city and the county seat of Marshall County, Kentucky, United States. The current mayor of this city is Rita Dotson. The population was 4,756 at the 2020 census. Benton was founded in 1842 by John Bearden and Francis H. Clayton. The town was named for Thomas Hart Benton, a senator from Missouri. Benton was then incorporated in 1845.