| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Eaton | 1 | 8,310 | 8,392 | -0.2% | 1,293 | 6 | City |
| Camden | 2 | 1,983 | 1,988 | -0.05% | 1,598 | 1 | Village |
| Lewisburg | 3 | 1,730 | 1,752 | -0.23% | 1,594 | 1 | Village |
| New Paris | 4 | 1,478 | 1,489 | -0.14% | 2,011 | 1 | Village |
| West Alexandria | 5 | 1,308 | 1,325 | -0.23% | 1,503 | 1 | Village |
| Gratis | 6 | 833 | 841 | -0.24% | 859 | 1 | Village |
| Eldorado | 7 | 445 | 454 | -0.45% | 1,943 | 0 | Village |
| West Manchester | 8 | 409 | 417 | -0.49% | 1,504 | 0 | Village |
| Verona | 9 | 399 | 403 | -0.25% | 875 | 0 | Village |
| West Elkton | 10 | 155 | 158 | -0.64% | 266 | 1 | Village |
Eaton is the largest city in Preble County, with a population of 8,310.
West Elkton is the smallest city in Preble County, with a population of 155.
There are 10 cities in Preble County, Ohio.