31 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Concord | 1 | 32,983 | 31,487 | 0.95% | 918 | 36 | Township |
| Troy | 2 | 27,490 | 26,385 | 0.67% | 2,176 | 13 | City |
| Piqua | 3 | 21,205 | 20,410 | 0.63% | 1,612 | 13 | City |
| Tipp City | 4 | 10,743 | 10,302 | 0.69% | 1,311 | 8 | City |
| Union | 5 | 10,055 | 9,592 | 0.94% | 212 | 47 | Township |
| Union | 6 | 7,164 | 6,900 | 0.62% | 844 | 8 | City |
| Troy | 7 | 7,076 | 7,115 | -0.11% | 319 | 22 | Township |
| Newberry | 8 | 6,701 | 6,406 | 0.92% | 158 | 42 | Township |
| West Milton | 9 | 4,928 | 4,709 | 0.76% | 1,453 | 3 | Village |
| Troy | 10 | 4,176 | 4,100 | 0.29% | 140 | 30 | Township |
| Newton | 11 | 3,674 | 3,510 | 0.93% | 88 | 42 | Township |
| Troy | 12 | 2,791 | 2,775 | 0.07% | 111 | 25 | Township |
| Covington | 13 | 2,655 | 2,555 | 0.64% | 1,937 | 1 | Village |
| Staunton | 14 | 2,541 | 2,424 | 0.95% | 97 | 26 | Township |
| Troy | 15 | 2,494 | 2,481 | 0.48% | 69 | 36 | Township |
| Troy | 16 | 2,480 | 2,112 | 2.06% | 106 | 23 | Township |
| Springcreek | 17 | 2,259 | 2,161 | 0.89% | 102 | 22 | Township |
| Bradford | 18 | 1,810 | 1,791 | 0.17% | 2,170 | 1 | Village |
| Elizabeth | 19 | 1,741 | 1,665 | 0.93% | 58 | 30 | Township |
| Lostcreek | 20 | 1,686 | 1,614 | 0.84% | 56 | 30 | Township |
| Washington | 21 | 1,553 | 1,480 | 0.98% | 74 | 21 | Township |
| Pleasant Hill | 22 | 1,283 | 1,232 | 0.71% | 2,040 | 1 | Village |
| Troy | 23 | 1,240 | 1,188 | 0.73% | 87 | 14 | Township |
| Brown | 24 | 1,202 | 1,148 | 0.84% | 40 | 30 | Township |
| Troy | 25 | 1,102 | 1,102 | 0.18% | 66 | 17 | Township |
| Fletcher | 26 | 468 | 450 | 0.65% | 1,505 | 0 | Village |
| Laura | 27 | 419 | 400 | 0.72% | 1,563 | 0 | Village |
| Casstown | 28 | 279 | 269 | 0.72% | 2,876 | 0 | Village |
| Potsdam | 29 | 231 | 231 | 0% | 518 | 0 | Village |
| Ludlow Falls | 30 | 181 | 172 | 1.12% | 1,011 | 0 | Village |
| Lockington | 31 | 155 | 160 | -0.64% | 1,845 | 0 | Village |
Concord is the largest city in Miami County, with a population of 32,983.
Lockington is the smallest city in Miami County, with a population of 155.
There are 31 cities in Miami County, Ohio.