to the U.S. Census Bureau, the county has a total area of 156 sqmi, of which 152 sqmi is land and 4.6 sqmi (2.9%) is water. It is the fifth-smallest county in Kentucky by land area and fourth-smallest by total area. The county's western border with Indiana is formed by the Ohio River.

The county is largely divided into two by a central roughly north-south ridge; to the east of which lie the Little Kentucky River