Hardin County is a county located in the west central portion of the U.S. state of Ohio. As of the 2020 census, the population was 30,696. Its county seat and largest city is Kenton. The county was created in 1820 and later organized in 1833. It is named for John Hardin, an officer in the American Revolution.

Kenton is a city in and the county seat of Hardin County, Ohio, United States, located in the west-central part of Ohio about 57 mi (92 km) northwest of Columbus and 70 mi (113 km) south of Toledo. Its population was 7,947 at the 2020 census. The city was named for frontiersman Simon Kenton of Kentucky and Ohio.