Carter County is a county located in the U.S. state of Kentucky. As of the 2020 census, the population was 26,627. Its county seat is Grayson. Carter County is in the Huntington-Ashland, WV-KY-OH Metropolitan Statistical Area. It is home to Carter Caves State Resort Park.

The Huntington–Ashland metropolitan area is a metropolitan area in the Appalachian Plateau region of the United States. Referred to locally as the "Tri-State area," and colloquially as "Kyova", the region spans seven counties in the three states of Kentucky, Ohio, and West Virginia. With a population of 361,580, the Tri-State area is nestled along the banks of the Ohio River. The region offers a diverse range of outdoor activities.