Fayette County is a county located in the central part of the U.S. state of Kentucky and is consolidated with the city of Lexington. As of the 2020 census, the population was 322,570, making it the second-most populous county in the commonwealth. Since 1974, its territory, population and government have been shared with Lexington. Fayette County is par…Fayette County is a county located in the central part of the U.S. state of Kentucky and is consolidated with the city of Lexington. As of the 2020 census, the population was 322,570, making it the second-most populous county in the commonwealth. Since 1974, its territory, population and government have been shared with Lexington. Fayette County is part of the Lexington-Fayette, KY Metropolitan Statistical Area.