| Zip Code | City | Population ↓ |
|---|---|---|
| 43326 | Kenton | 12,990 |
| 45810 | Ada | 7,654 |
| 45843 | Forest | 3,769 |
| 43310 | Belle Center | 2,734 |
| 43340 | Mount Victory | 2,001 |
| 45812 | Alger | 1,881 |
| 45836 | Dunkirk | 1,435 |
| 45835 | Dola | 428 |
| 45859 | McGuffey | 380 |
| 43346 | Roundhead | 201 |
The data shown reflect ZCTAs from the US Census. As of 2024, there are 10 ZCTAs in Hardin County, Ohio (US Census).