Campbellsville is in and the county seat of Taylor County, Kentucky, United States. The population within city limits was 10,604 at the 2010 U.S. census. It is the site of Campbellsville University, a private institution. On the border is Green River Lake, established for flood control and now the center of a popular park. Campbellsville is twinned with Buncrana in County Donegal, Republic of Ireland.