17 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| London | 1 | 10,709 | 10,268 | 0.83% | 1,275 | 8 | City |
| Union | 2 | 6,718 | 5,868 | 9.06% | 174 | 39 | Township |
| West Jefferson | 3 | 4,710 | 4,155 | 2.41% | 475 | 10 | Village |
| Plain City | 4 | 4,467 | 4,144 | 1.48% | 1,624 | 3 | Village |
| Darby | 5 | 4,447 | 4,267 | 0.02% | 210 | 21 | Township |
| Pleasant | 6 | 3,468 | 3,262 | 1.58% | 112 | 31 | Township |
| Somerford | 7 | 3,076 | 3,056 | 0.03% | 101 | 30 | Township |
| Canaan | 8 | 2,704 | 2,658 | 0.26% | 78 | 35 | Township |
| Mount Sterling | 9 | 2,089 | 1,941 | 1.46% | 1,238 | 2 | Village |
| Range | 10 | 977 | 969 | 0.21% | 20 | 48 | Township |
| Deer Creek | 11 | 921 | 919 | -0.11% | 30 | 31 | Township |
| Stokes | 12 | 640 | 642 | -0.31% | 18 | 35 | Township |
| Pike | 13 | 573 | 541 | 1.06% | 22 | 26 | Township |
| Paint | 14 | 566 | 564 | 0% | 15 | 37 | Township |
| Oak Run | 15 | 523 | 515 | 0.38% | 19 | 28 | Township |
| South Solon | 16 | 326 | 325 | 0% | 1,387 | 0 | Village |
| Midway | 17 | 269 | 269 | 0% | 1,035 | 0 | Village |
London is the largest city in Madison County, with a population of 10,709.
Midway is the smallest city in Madison County, with a population of 269.
There are 17 cities in Madison County, Ohio.