31 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Byron township | 1 | 28,209 | 27,028 | 0.69% | 784 | 36 | Township |
| Owosso | 2 | 14,505 | 14,695 | -0.26% | 2,764 | 5.25 | City |
| Owosso charter township | 3 | 4,807 | 4,766 | 0.17% | 152 | 31.66 | Township |
| Vernon township | 4 | 4,360 | 4,279 | 0.53% | 129 | 33.85 | Township |
| Caledonia charter township | 5 | 4,340 | 4,346 | 0.07% | 140 | 31.11 | Township |
| Perry township | 6 | 4,210 | 4,157 | 0.26% | 133 | 31.63 | Township |
| Woodhull township | 7 | 3,723 | 3,680 | 0.3% | 146 | 25.53 | Township |
| Durand | 8 | 3,451 | 3,498 | -0.26% | 1,767 | 1.95 | City |
| Burns township | 9 | 3,293 | 3,274 | 0.21% | 93 | 35.30 | Township |
| Bennington township | 10 | 3,133 | 3,109 | 0.22% | 88 | 35.58 | Township |
| Corunna | 11 | 3,007 | 3,044 | -0.23% | 945 | 3.18 | City |
| Shiawassee township | 12 | 2,748 | 2,733 | 0.18% | 76 | 36.39 | Township |
| Venice township | 13 | 2,450 | 2,421 | 0.29% | 65 | 37.44 | Township |
| Perry | 14 | 2,164 | 2,069 | 0.89% | 860 | 2.52 | City |
| Antrim township | 15 | 2,124 | 2,109 | 0.24% | 60 | 35.34 | Township |
| Hazelton township | 16 | 2,046 | 2,051 | 0% | 55 | 37.29 | Township |
| Sciota township | 17 | 1,689 | 1,688 | 0.06% | 67 | 25.20 | Township |
| Middlebury township | 18 | 1,541 | 1,528 | 0.26% | 63 | 24.60 | Township |
| Laingsburg | 19 | 1,404 | 1,428 | -0.35% | 885 | 1.59 | City |
| Vernon township | 20 | 1,311 | 1,302 | -0.15% | 37 | 35.31 | Township |
| Rush township | 21 | 1,265 | 1,264 | 0.08% | 36 | 34.90 | Township |
| Morrice | 22 | 1,007 | 966 | 0.8% | 773 | 1.30 | Village |
| Vernon | 23 | 718 | 732 | -0.42% | 721 | 1 | Village |
| Middletown | 24 | 676 | 839 | -2.03% | 1,441 | 0.47 | CDP |
| Fairfield township | 25 | 653 | 652 | 0.15% | 26 | 25.06 | Township |
| New Lothrop | 26 | 579 | 588 | -0.34% | 669 | 0.86 | Village |
| Byron | 27 | 525 | 532 | -0.19% | 744 | 0.71 | Village |
| Shaftsburg | 28 | 522 | 293 | 6.97% | 522 | 1 | CDP |
| Bancroft | 29 | 479 | 478 | 0% | 809 | 0.59 | Village |
| Henderson | 30 | 260 | 350 | -3.7% | 72 | 3.60 | CDP |
| Henderson township | 31 | 187 | 183 | 0.54% | 5 | 36.16 | Township |
Byron township is the largest city in Shiawassee County, with a population of 28,209.
Henderson township is the smallest city in Shiawassee County.
There are 31 cities in Shiawassee County, Michigan.