18 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Kankakee | 1 | 23,299 | 24,007 | -0.5% | 1,538 | 15 | City |
| Bourbonnais | 2 | 18,076 | 18,096 | -0.02% | 1,942 | 9 | Village |
| Bradley | 3 | 15,255 | 15,383 | -0.14% | 2,097 | 7 | Village |
| Manteno | 4 | 9,268 | 9,186 | 0.15% | 1,732 | 5 | Village |
| Momence | 5 | 3,134 | 3,239 | -0.54% | 1,985 | 2 | City |
| Limestone | 6 | 1,513 | 1,546 | -0.33% | 543 | 3 | Village |
| Herscher | 7 | 1,481 | 1,517 | -0.4% | 817 | 2 | Village |
| Grant Park | 8 | 1,278 | 1,289 | -0.16% | 374 | 3 | Village |
| St. Anne | 9 | 1,117 | 1,156 | -0.53% | 1,346 | 1 | Village |
| Essex | 10 | 860 | 839 | 0.47% | 370 | 2 | Village |
| Aroma Park | 11 | 648 | 663 | -0.31% | 344 | 2 | Village |
| Hopkins Park | 12 | 635 | 605 | 0.79% | 152 | 4 | Village |
| Bonfield | 13 | 338 | 350 | -0.59% | 687 | 0 | Village |
| Buckingham | 14 | 236 | 241 | -0.42% | 940 | 0 | Village |
| Sammons Point | 15 | 213 | 218 | -0.47% | 115 | 2 | Village |
| Reddick | 16 | 193 | 198 | -0.52% | 808 | 0 | Village |
| Irwin | 17 | 66 | 68 | 0% | 1,467 | 0 | Village |
| Union Hill | 18 | 51 | 53 | 0% | 785 | 0 | Village |
Kankakee is the largest city in Kankakee County, with a population of 23,299.
Union Hill is the smallest city in Kankakee County, with a population of 51.
There are 18 cities in Kankakee County, Illinois.