8 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Sidney | 1 | 20,150 | 20,547 | -0.39% | 1,683 | 11.97 | City |
| Fort Loramie | 2 | 1,578 | 1,598 | -0.25% | 1,529 | 1.03 | Village |
| Anna | 3 | 1,453 | 1,470 | -0.21% | 1,311 | 1.11 | Village |
| Jackson Center | 4 | 1,426 | 1,441 | -0.21% | 829 | 1.72 | Village |
| Botkins | 5 | 1,188 | 1,157 | 0.51% | 941 | 1.26 | Village |
| Russia | 6 | 724 | 724 | 0% | 835 | 0.87 | Village |
| Port Jefferson | 7 | 304 | 308 | -0.33% | 2,000 | 0.15 | Village |
| Kettlersville | 8 | 157 | 166 | -1.26% | 153 | 1.03 | Village |
Sidney is the largest city in Shelby County, with a population of 20,150.
Kettlersville is the smallest city in Shelby County.
There are 8 cities in Shelby County, Ohio.