Founded in Apr 1, 1820, Putnam County is one of 88 counties in the state of Ohio. Historically, Putnam County was formed from Shelby County. The city of Ottawa is the county seat. With FIPS code of 137, Putnam County has a population of 34,318 and area of 483.87 square miles (1,253 km2).
List of all cities in Putnam County, OH alphabetically
| City/Town | Postal Code | Area Code |
| Belmore, OH | 45815 | 419/567 |
| Cloverdale, OH | 45827 | 419/567 |
| Cols Grove, OH | 45830 | 419/567 |
| Columbus Grove, OH | 45830 | 419/567 |
| Continental, OH | 45831 | 419/567 |
| 45837 | 419/567 | |
| Dupont, OH | 45837 | 419/567 |
| Fort Jennings, OH | 45844 | 419/567 |
| Gilboa, OH | 45875 | 419/567 |
| Glandorf, OH | 45848 | 419/567 |
| Kalida, OH | 45853 | 419/567 |
| Leipsic, OH | 45815 | 419/567 |
| 45856 | 419/567 | |
| Miller City, OH | 45864 | 419/567 |
| Ottawa, OH | 45875 | 419/567 |
| Ottoville, OH | 45876 | 419/567 |
| Pandora, OH | 45877 | 419/567 |
| Vaughnsville, OH | 45893 | 419/567 |
| West Leipsic, OH | 45856 | 419/567 |