8 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Kenton | 1 | 7,764 | 7,954 | -0.49% | 1,553 | 5 | City |
| Ada | 2 | 5,280 | 5,334 | -0.21% | 2,474 | 2.13 | Village |
| Forest | 3 | 1,317 | 1,351 | -0.53% | 788 | 1.67 | Village |
| Alger | 4 | 813 | 840 | -0.61% | 2,747 | 0.30 | Village |
| Dunkirk | 5 | 745 | 774 | -0.8% | 1,132 | 0.66 | Village |
| Mount Victory | 6 | 588 | 605 | -0.51% | 697 | 0.84 | Village |
| Ridgeway | 7 | 311 | 318 | -0.32% | 549 | 0.57 | Village |
| Dola | 8 | 135 | 141 | 0% | 162 | 0.83 | CDP |
Kenton is the largest city in Hardin County, with a population of 7,764.
Dola is the smallest city in Hardin County.
There are 8 cities in Hardin County, Ohio.