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 reïncorporated in 1856. Union College and the Appalachian Children's Home are located in Barbourville.