Knox County is a county located in Appalachia near the southeastern corner of the U.S. state of Kentucky. As of the 2020 census, the population was 30,193. Its county seat is Barbourville. The county is named for General Henry Knox. It is one of the few coal-producing counties in Kentucky that has not suffered massive population loss. Knox County is included in the London, KY Micropolitan Statistical Area.

Barbourville is a home rule-class city in Knox County, Kentucky, in the United States. The population was 3,165 at the 2010 census, down from 3,589 at the 2000 census. It is the county seat of Knox County. The city was formally established by the state assembly in 1812. It was incorporated in 1854 and then reincorporated in 1856.