23 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Marion | 1 | 11,906 | 11,272 | 0% | 341 | 35 | Township |
| Leroy | 2 | 3,925 | 3,792 | 1.03% | 115 | 34 | Township |
| Leroy | 3 | 3,689 | 3,658 | 0.14% | 102 | 36 | Township |
| Reed City | 4 | 2,543 | 2,483 | 0.47% | 1,210 | 2 | City |
| Hersey | 5 | 2,013 | 1,944 | 0.9% | 57 | 35 | Township |
| Evart | 6 | 1,790 | 1,749 | 0.45% | 727 | 2 | City |
| Marion | 7 | 1,656 | 1,657 | 0.06% | 65 | 26 | Township |
| Marion | 8 | 1,613 | 1,561 | 0.88% | 44 | 37 | Township |
| Marion | 9 | 1,559 | 1,571 | -0.26% | 43 | 36 | Township |
| Rose Lake | 10 | 1,471 | 1,407 | 0.96% | 44 | 34 | Township |
| Burdell | 11 | 1,452 | 1,409 | 0.76% | 39 | 37 | Township |
| Evart | 12 | 1,387 | 1,341 | 0.8% | 42 | 33 | Township |
| Le Roy | 13 | 1,297 | 1,249 | 0.93% | 37 | 35 | Township |
| Sherman | 14 | 1,021 | 990 | 0.69% | 28 | 37 | Township |
| Sylvan | 15 | 1,011 | 975 | 0.9% | 29 | 35 | Township |
| Osceola | 16 | 985 | 950 | 0.92% | 29 | 34 | Township |
| Marion | 17 | 802 | 781 | 0.5% | 623 | 1 | Village |
| Middle Branch | 18 | 802 | 775 | 0.75% | 23 | 35 | Township |
| Marion | 19 | 773 | 761 | 0.65% | 32 | 24 | Township |
| Orient | 20 | 754 | 728 | 0.94% | 22 | 35 | Township |
| Hartwick | 21 | 608 | 590 | 0.66% | 17 | 35 | Township |
| Hersey | 22 | 367 | 357 | 0.55% | 334 | 1 | Village |
| Tustin | 23 | 255 | 252 | 0% | 657 | 0 | Village |
Marion is the largest city in Osceola County, with a population of 11,906.
Tustin is the smallest city in Osceola County, with a population of 255.
There are 23 cities in Osceola County, Michigan.