31 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Byron | 1 | 28,854 | 27,025 | 1.58% | 802 | 36 | Township |
| Owosso | 2 | 14,506 | 14,695 | -0.26% | 2,764 | 5 | City |
| Owosso charter | 3 | 4,800 | 4,766 | 0.13% | 152 | 32 | Township |
| Vernon | 4 | 4,324 | 4,274 | 0.19% | 128 | 34 | Township |
| Caledonia charter | 5 | 4,312 | 4,346 | -0.23% | 139 | 31 | Township |
| Perry | 6 | 4,189 | 4,147 | 0.1% | 132 | 32 | Township |
| Woodhull | 7 | 3,701 | 3,682 | 0.03% | 145 | 26 | Township |
| Durand | 8 | 3,479 | 3,498 | -0.11% | 1,781 | 2 | City |
| Burns | 9 | 3,281 | 3,274 | 0% | 93 | 35 | Township |
| Bennington | 10 | 3,122 | 3,109 | 0.1% | 88 | 36 | Township |
| Corunna | 11 | 3,006 | 3,045 | -0.27% | 945 | 3 | City |
| Shiawassee | 12 | 2,734 | 2,735 | -0.07% | 75 | 36 | Township |
| Venice | 13 | 2,439 | 2,422 | 0.08% | 65 | 37 | Township |
| Perry | 14 | 2,143 | 2,073 | 0.66% | 852 | 3 | City |
| Antrim | 15 | 2,114 | 2,111 | -0.05% | 60 | 35 | Township |
| Hazelton | 16 | 2,044 | 2,051 | -0.05% | 55 | 37 | Township |
| Sciota | 17 | 1,687 | 1,689 | 0% | 67 | 25 | Township |
| Middlebury | 18 | 1,537 | 1,529 | 0.07% | 62 | 25 | Township |
| Laingsburg | 19 | 1,407 | 1,427 | -0.28% | 887 | 2 | City |
| Vernon | 20 | 1,350 | 1,301 | 1.12% | 38 | 35 | Township |
| Rush | 21 | 1,262 | 1,263 | 0% | 36 | 35 | Township |
| Morrice | 22 | 991 | 963 | 0.51% | 761 | 1 | Village |
| Vernon | 23 | 713 | 728 | -0.42% | 716 | 1 | Village |
| Middletown | 24 | 676 | 839 | -2.03% | 1,441 | 0 | CDP |
| Fairfield | 25 | 648 | 651 | -0.15% | 26 | 25 | Township |
| New Lothrop | 26 | 579 | 587 | -0.34% | 669 | 1 | Village |
| Byron | 27 | 525 | 532 | -0.38% | 744 | 1 | Village |
| Shaftsburg | 28 | 522 | 293 | 6.97% | 522 | 1 | CDP |
| Bancroft | 29 | 472 | 477 | -0.21% | 797 | 1 | Village |
| Henderson | 30 | 260 | 350 | -3.7% | 72 | 4 | CDP |
| Henderson | 31 | 191 | 183 | 1.06% | 5 | 36 | Township |
Byron is the largest city in Shiawassee County, with a population of 28,854.
Henderson is the smallest city in Shiawassee County, with a population of 191.
There are 31 cities in Shiawassee County, Michigan.