Lexington County is a county located in the U.S. state of South Carolina. As of the 2020 census, the population was 293,991. Its county seat and largest community is Lexington. The county was chartered in 1785 and was named in commemoration of Lexington, Massachusetts, the site of the Battle of Lexington in the American Revolutionary War. Lexington County is the sixth-most populous county in South Carolina by population and is part of the Columbia, SC Metropolitan Statistical Area. It is located in the Midlands region of South Carolina.

Lexington is the most populous town in and the county seat of Lexington County, South Carolina, United States. It is a suburb of the state capital, Columbia. The population was 23,568 at the 2020 Census, and it is the second-most populous municipality in the greater Columbia area. The 2022 estimated population is 24,626. According to the Central Midlands Council of Governments, the greater Lexington area had an estimated population of 111,549 in 2020 and is considered the fastest-growing area in the Midlands. Lexington's town limits are bordered to the east by the city of West Columbia.