14 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Troy | 1 | 27,490 | 26,385 | 0.67% | 2,176 | 13 | City |
| Piqua | 2 | 21,205 | 20,410 | 0.63% | 1,612 | 13 | City |
| Tipp City | 3 | 10,743 | 10,302 | 0.69% | 1,311 | 8 | City |
| Union | 4 | 7,164 | 6,900 | 0.62% | 844 | 8 | City |
| West Milton | 5 | 4,928 | 4,709 | 0.76% | 1,453 | 3 | Village |
| Covington | 6 | 2,655 | 2,555 | 0.64% | 1,937 | 1 | Village |
| Bradford | 7 | 1,810 | 1,791 | 0.17% | 2,170 | 1 | Village |
| Pleasant Hill | 8 | 1,283 | 1,232 | 0.71% | 2,040 | 1 | Village |
| Fletcher | 9 | 468 | 450 | 0.65% | 1,505 | 0 | Village |
| Laura | 10 | 419 | 400 | 0.72% | 1,563 | 0 | Village |
| Casstown | 11 | 279 | 269 | 0.72% | 2,876 | 0 | Village |
| Potsdam | 12 | 231 | 231 | 0% | 518 | 0 | Village |
| Ludlow Falls | 13 | 181 | 172 | 1.12% | 1,011 | 0 | Village |
| Lockington | 14 | 155 | 160 | -0.64% | 1,845 | 0 | Village |
Troy is the largest city in Miami County, with a population of 27,490.
Lockington is the smallest city in Miami County, with a population of 155.
There are 14 cities in Miami County, Ohio.