Founded in Apr 1, 1808, Delaware County is one of 88 counties in the state of Ohio. Historically, Delaware County was formed from Franklin County. The city of Delaware is the county seat. With FIPS code of 41, Delaware County has a population of 220,740 and area of 442.41 square miles (1,146 km2).
List of all cities in Delaware County, OH alphabetically
| City/Town | Postal Code | Area Code |
| Ashley, OH | 43003 | 740 |
| Columbus, OH | 43240 | 614/380 |
| Delaware, OH | 43015 | 740 |
| Galena, OH | 43021 | 740 |
| Kilbourne, OH | 43032 | 740 |
| Lewis Center, OH | 43035 | 740 |
| Ostrander, OH | 43061 | 740 |
| Powell, OH | 43065 | 614/380 |
| Radnor, OH | 43066 | 740 |
| Shawnee Hills, OH | 43065 | 614/380 |
| Sunbury, OH | 43074 | 740 |
| Westerville, OH | 43082 | 614/380 |