Highland County is a county located in the U.S. state of Ohio. As of the 2020 census, the population was 43,317. Its county seat is Hillsboro. The county is named for the topography which is hilly and divides the watersheds of the Little Miami and Scioto Rivers.

Hillsboro is a city in and the county seat of Highland County, Ohio, United States, approximately 35 miles (56 km) west of Chillicothe and 50 miles (80 km) east of Cincinnati. The population was 6,481 at the 2020 census.