| Zip Code | City | Population ↓ |
|---|---|---|
| 44883 | Tiffin | 28,667 |
| 44830 | Fostoria | 18,176 |
| 44867 | Republic | 2,640 |
| 44836 | Green Springs | 2,564 |
| 44818 | Bloomville | 2,279 |
| 44807 | Attica | 2,049 |
| 44853 | New Riegel | 1,460 |
| 44802 | Alvada | 956 |
| 44815 | Bettsville | 811 |
| 44844 | McCutchenville | 712 |
| 44841 | Kansas | 670 |
| 44828 | Flat Rock | 186 |
| 44861 | Old Fort | 129 |
| 44809 | Bascom | 106 |
The data shown reflect ZCTAs from the US Census. As of 2024, there are 14 ZCTAs in Seneca County, Ohio (US Census).