| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Champaign | 1 | 91,753 | 88,385 | 0.61% | 3,985 | 23 | City |
| Urbana | 2 | 39,924 | 38,862 | 0.52% | 3,372 | 12 | City |
| Rantoul | 3 | 11,913 | 12,322 | -0.65% | 1,403 | 8 | Village |
| Mahomet | 4 | 10,741 | 9,491 | 2.14% | 1,105 | 10 | Village |
| Savoy | 5 | 9,163 | 8,868 | 0.55% | 2,788 | 3 | Village |
| St. Joseph | 6 | 3,664 | 3,794 | -0.68% | 1,759 | 2 | Village |
| Tolono | 7 | 3,479 | 3,581 | -0.57% | 1,688 | 2 | Village |
| Fisher | 8 | 2,087 | 2,053 | 0% | 1,569 | 1 | Village |
| Philo | 9 | 1,343 | 1,389 | -0.67% | 1,620 | 1 | Village |
| Sidney | 10 | 1,158 | 1,202 | -0.77% | 1,856 | 1 | Village |
| Homer | 11 | 1,044 | 1,074 | -0.57% | 1,065 | 1 | Village |
| Thomasboro | 12 | 996 | 1,031 | -0.7% | 996 | 1 | Village |
| Gifford | 13 | 880 | 902 | -0.56% | 1,982 | 0 | Village |
| Ogden | 14 | 710 | 731 | -0.56% | 1,207 | 1 | Village |
| Pesotum | 15 | 543 | 551 | -0.55% | 954 | 1 | Village |
| Sadorus | 16 | 388 | 399 | -0.51% | 378 | 1 | Village |
| Bondville | 17 | 372 | 386 | -0.8% | 1,482 | 0 | Village |
| Broadlands | 18 | 300 | 313 | -0.99% | 932 | 0 | Village |
| Ludlow | 19 | 295 | 306 | -0.67% | 743 | 0 | Village |
| Royal | 20 | 277 | 289 | -1.07% | 1,514 | 0 | Village |
| Ivesdale | 21 | 253 | 263 | -0.78% | 353 | 1 | Village |
| Longview | 22 | 110 | 114 | -0.9% | 445 | 0 | Village |
| Foosland | 23 | 72 | 75 | -1.37% | 1,043 | 0 | Village |
Champaign is the largest city in Champaign County, with a population of 91,753.
Foosland is the smallest city in Champaign County, with a population of 72.
There are 23 cities in Champaign County, Illinois.