17 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Marion township | 1 | 12,304 | 11,271 | 1.65% | 353 | 34.89 | Township |
| Leroy township | 2 | 3,800 | 3,792 | 0.05% | 111 | 34.13 | Township |
| Leroy township | 3 | 3,693 | 3,659 | 0.16% | 103 | 36 | Township |
| Reed City | 4 | 2,543 | 2,487 | 0.43% | 1,210 | 2.10 | City |
| Hersey township | 5 | 1,988 | 1,945 | 0.2% | 56 | 35.35 | Township |
| Evart | 6 | 1,778 | 1,745 | 0.4% | 722 | 2.46 | City |
| Marion township | 7 | 1,650 | 1,656 | -0.24% | 65 | 25.57 | Township |
| Marion township | 8 | 1,595 | 1,564 | 0.19% | 43 | 36.97 | Township |
| Marion township | 9 | 1,552 | 1,568 | -0.32% | 43 | 36.08 | Township |
| Rose Lake township | 10 | 1,464 | 1,407 | 0.55% | 44 | 33.61 | Township |
| Burdell township | 11 | 1,441 | 1,413 | 0.14% | 39 | 37.27 | Township |
| Evart township | 12 | 1,372 | 1,341 | 0.22% | 42 | 32.68 | Township |
| Le Roy township | 13 | 1,290 | 1,251 | 0.39% | 37 | 34.99 | Township |
| Sherman township | 14 | 1,005 | 0 | -0.1% | 27 | 37.03 | Township |
| Marion | 15 | 801 | 783 | 0.5% | 622 | 1.29 | Village |
| Hersey | 16 | 367 | 357 | 0.55% | 334 | 1.10 | Village |
| Tustin | 17 | 259 | 253 | 0.39% | 668 | 0.39 | Village |
Marion township is the largest city in Osceola County, with a population of 12,304.
Tustin is the smallest city in Osceola County.
There are 17 cities in Osceola County, Michigan.