15 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Sidney | 1 | 20,352 | 20,550 | -0.2% | 1,700 | 12 | City |
| Dinsmore | 2 | 3,408 | 3,373 | 0.44% | 94 | 36 | Township |
| McLean | 3 | 3,365 | 3,375 | 0.18% | 104 | 32 | Township |
| Loramie | 4 | 2,634 | 2,598 | 0.84% | 75 | 35 | Township |
| Cynthian | 5 | 1,998 | 1,999 | 0.3% | 64 | 31 | Township |
| Washington | 6 | 1,945 | 1,949 | 0.26% | 79 | 25 | Township |
| Fort Loramie | 7 | 1,585 | 1,602 | -0.25% | 1,536 | 1 | Village |
| Turtle Creek | 8 | 1,562 | 1,561 | 0.32% | 52 | 30 | Township |
| Anna | 9 | 1,464 | 1,469 | -0.07% | 1,321 | 1 | Village |
| Jackson Center | 10 | 1,437 | 1,441 | -0.07% | 835 | 2 | Village |
| Botkins | 11 | 1,189 | 1,157 | 0.51% | 941 | 1 | Village |
| Orange | 12 | 1,130 | 1,123 | 0.44% | 50 | 23 | Township |
| Russia | 13 | 748 | 723 | 0.67% | 863 | 1 | Village |
| Port Jefferson | 14 | 300 | 308 | -0.66% | 1,974 | 0 | Village |
| Kettlersville | 15 | 163 | 167 | -0.61% | 158 | 1 | Village |
Sidney is the largest city in Shelby County, with a population of 20,352.
Kettlersville is the smallest city in Shelby County, with a population of 163.
There are 15 cities in Shelby County, Ohio.