31 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Concord | 1 | 32,674 | 31,487 | 0.95% | 909 | 36 | Township |
| Troy | 2 | 27,306 | 26,385 | 0.68% | 2,222 | 12 | City |
| Piqua | 3 | 21,072 | 20,410 | 0.63% | 1,625 | 13 | City |
| Tipp City | 4 | 10,669 | 10,302 | 0.69% | 1,328 | 8 | City |
| Union | 5 | 9,961 | 9,592 | 0.95% | 210 | 47 | Township |
| Union | 6 | 7,120 | 6,900 | 0.62% | 858 | 8 | City |
| Troy | 7 | 7,084 | 7,115 | -0.11% | 319 | 22 | Township |
| Newberry | 8 | 6,640 | 6,406 | 0.93% | 157 | 42 | Township |
| West Milton | 9 | 4,891 | 4,709 | 0.74% | 1,442 | 3 | Village |
| Troy | 10 | 4,164 | 4,100 | 0.29% | 140 | 30 | Township |
| Newton | 11 | 3,640 | 3,510 | 0.94% | 87 | 42 | Township |
| Troy | 12 | 2,789 | 2,775 | 0.07% | 111 | 25 | Township |
| Covington | 13 | 2,638 | 2,555 | 0.61% | 1,924 | 1 | Village |
| Staunton | 14 | 2,517 | 2,424 | 0.96% | 96 | 26 | Township |
| Troy | 15 | 2,482 | 2,481 | 0.49% | 69 | 36 | Township |
| Troy | 16 | 2,430 | 2,112 | 2.1% | 104 | 23 | Township |
| Springcreek | 17 | 2,239 | 2,161 | 0.9% | 101 | 22 | Township |
| Bradford | 18 | 1,807 | 1,791 | 0.17% | 2,167 | 1 | Village |
| Elizabeth | 19 | 1,725 | 1,665 | 0.94% | 58 | 30 | Township |
| Lostcreek | 20 | 1,672 | 1,614 | 0.84% | 56 | 30 | Township |
| Washington | 21 | 1,538 | 1,480 | 0.98% | 73 | 21 | Township |
| Pleasant Hill | 22 | 1,274 | 1,232 | 0.63% | 2,025 | 1 | Village |
| Troy | 23 | 1,231 | 1,188 | 0.74% | 86 | 14 | Township |
| Brown | 24 | 1,192 | 1,148 | 0.85% | 39 | 30 | Township |
| Troy | 25 | 1,100 | 1,102 | 0.18% | 66 | 17 | Township |
| Fletcher | 26 | 465 | 450 | 0.65% | 1,495 | 0 | Village |
| Laura | 27 | 416 | 400 | 0.73% | 1,552 | 0 | Village |
| Casstown | 28 | 277 | 269 | 0.36% | 2,856 | 0 | Village |
| Potsdam | 29 | 231 | 231 | 0% | 518 | 0 | Village |
| Ludlow Falls | 30 | 179 | 172 | 0.56% | 1,000 | 0 | Village |
| Lockington | 31 | 156 | 160 | -0.64% | 1,857 | 0 | Village |
Concord is the largest city in Miami County, with a population of 32,674.
Lockington is the smallest city in Miami County, with a population of 156.
There are 31 cities in Miami County, Ohio.