Founded in Mar 1, 1810, Clinton County is one of 88 counties in the state of Ohio. Historically, Clinton County was formed from Highland and Warren Counties. The city of Wilmington is the county seat. With FIPS code of 27, Clinton County has a population of 42,004 and area of 410.88 square miles (1,064 km2).
List of all cities in Clinton County, OH alphabetically
| City/Town | Postal Code | Area Code |
| Blanchester, OH | 45107 | 937 |
| Clarksville, OH | 45113 | 937 |
| Clinton County, OH | 45169 | 937 |
| Cuba, OH | 45114 | 937 |
| Gist Settlement, OH | 45159 | 937 |
| Lees Creek, OH | 45138 | 937 |
| Martinsville, OH | 45146 | 937 |
| Midland, OH | 45148 | 937 |
| New Vienna, OH | 45159 | 937 |
| Port William, OH | 45164 | 937 |
| Reesville, OH | 45166 | 937 |
| Sabina, OH | 45169 | 937 |
| Westboro, OH | 45148 | 937 |
| Wilmington, OH | 45177 | 937 |