Founded in Apr 1, 1820, Hardin County is one of 88 counties in the state of Ohio. Historically, Hardin County was formed from Logan County. The city of Kenton is the county seat. With FIPS code of 65, Hardin County has a population of 30,621 and area of 470.29 square miles (1,218 km2).
List of all cities in Hardin County, OH alphabetically
| City/Town | Postal Code | Area Code |
| Ada, OH | 45810 | 419/567 |
| Alger, OH | 45812 | 419/567 |
| Dola, OH | 45835 | 419/567 |
| Dunkirk, OH | 45836 | 419/567 |
| Forest, OH | 45843 | 419/567 |
| Hepburn, OH | 43326 | 419/567 |
| Kenton, OH | 43326 | 419/567 |
| McGuffey, OH | 45859 | 419/567 |
| Mount Victory, OH | 43340 | 937 |
| Ridgeway, OH | 43345 | 937 |
| Roundhead, OH | 43346 | 937 |