Founded in Apr 7, 1845, Defiance County is one of 88 counties in the state of Ohio. Historically, Defiance County was formed from Williams, Henry, and Paulding Counties. The city of Defiance is the county seat. With FIPS code of 39, Defiance County has a population of 38,144 and area of 411.16 square miles (1,065 km2).
List of all cities in Defiance County, OH alphabetically
| City/Town | Postal Code | Area Code |
| Defiance, OH | 43512 | 419/567 |
| Evansport, OH | 43519 | 419/567 |
| Farmer, OH | 43520 | 419/567 |
| Hicksville, OH | 43526 | 419/567 |
| Jewell, OH | 43530 | 419/567 |
| Mark Center, OH | 43536 | 419/567 |
| Ney, OH | 43549 | 419/567 |
| Sherwood, OH | 43556 | 419/567 |
| Stryker, OH | 43519 | 419/567 |