Lexington is a consolidated city coterminous with and the county seat of Fayette County, Kentucky, United States. As of the 2020 census the …Lexington is a consolidated city coterminous with and the county seat of Fayette County, Kentucky, United States. As of the 2020 census the city's population was 322,570, making it the second-most populous city in Kentucky, the 14th-most populous city in the Southeast, and the 59th-most populous city in the United States. By land area, it is the country's 30th-largest city.