15 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 |
| Dinsmore township | 2 | 3,412 | 3,375 | 0.44% | 94 | 36.22 | Township |
| McLean township | 3 | 3,359 | 3,370 | 0.18% | 104 | 32.22 | Township |
| Loramie township | 4 | 2,615 | 2,598 | 0.46% | 74 | 35.32 | Township |
| Cynthian township | 5 | 1,992 | 2,002 | 0.1% | 64 | 31.07 | Township |
| Washington township | 6 | 1,935 | 1,949 | 0.1% | 78 | 24.66 | Township |
| Fort Loramie | 7 | 1,578 | 1,598 | -0.25% | 1,529 | 1.03 | Village |
| Turtle Creek township | 8 | 1,559 | 1,559 | 0.32% | 52 | 30.17 | Township |
| Anna | 9 | 1,453 | 1,470 | -0.21% | 1,311 | 1.11 | Village |
| Jackson Center | 10 | 1,426 | 1,441 | -0.21% | 829 | 1.72 | Village |
| Botkins | 11 | 1,188 | 1,157 | 0.51% | 941 | 1.26 | Village |
| Orange township | 12 | 1,127 | 1,122 | 0.36% | 50 | 22.69 | Township |
| Russia | 13 | 724 | 724 | 0% | 835 | 0.87 | Village |
| Port Jefferson | 14 | 304 | 308 | -0.33% | 2,000 | 0.15 | Village |
| Kettlersville | 15 | 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 15 cities in Shelby County, Ohio.