20 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Charleston | 1 | 19,255 | 19,621 | -0.3% | 518 | 37 | Township |
| Charleston | 2 | 17,252 | 17,579 | -0.31% | 1,901 | 9 | City |
| Mattoon | 3 | 16,476 | 16,853 | -0.38% | 1,597 | 10 | City |
| Mattoon | 4 | 14,354 | 14,610 | -0.13% | 397 | 36 | Township |
| Lafayette | 5 | 4,635 | 4,715 | -0.17% | 128 | 36 | Township |
| East Oakland | 6 | 1,201 | 1,227 | -0.33% | 31 | 39 | Township |
| Humboldt | 7 | 1,185 | 1,210 | -0.25% | 22 | 53 | Township |
| Pleasant Grove | 8 | 1,183 | 1,206 | -0.17% | 28 | 42 | Township |
| Ashmore | 9 | 1,113 | 1,141 | -0.36% | 21 | 54 | Township |
| North Okaw | 10 | 967 | 1,000 | -0.62% | 18 | 54 | Township |
| Paradise | 11 | 959 | 973 | -0.21% | 41 | 23 | Township |
| Hutton | 12 | 759 | 774 | -0.26% | 14 | 55 | Township |
| Oakland | 13 | 713 | 734 | -0.42% | 911 | 1 | City |
| Ashmore | 14 | 622 | 637 | -0.32% | 773 | 1 | Village |
| Humboldt | 15 | 354 | 360 | -0.28% | 1,032 | 0 | Village |
| Seven Hickory | 16 | 304 | 310 | -0.33% | 6 | 52 | Township |
| Morgan | 17 | 290 | 297 | -0.34% | 11 | 26 | Township |
| Lerna | 18 | 216 | 221 | -0.46% | 1,878 | 0 | Village |
| Allenville | 19 | 129 | 132 | 0% | 212 | 1 | Village |
| Oakland | 20 | 128 | 130 | 0% | 4 | 36 | Township |
Charleston is the largest city in Coles County, with a population of 19,255.
Oakland is the smallest city in Coles County, with a population of 128.
There are 20 cities in Coles County, Illinois.