Lexington is a city in Henderson County, Tennessee, United States. It is midway between Memphis and Nashville, lying 10 miles south of Inte…Lexington is a city in Henderson County, Tennessee, United States. It is midway between Memphis and Nashville, lying 10 miles south of Interstate 40, which connects the two cities. Its population was 7,956 at the 2020 census. It is the county seat of Henderson County.