| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Chester | 1 | 6,829 | 6,817 | -0.26% | 1,183 | 6 | City |
| Sparta | 2 | 4,009 | 4,078 | -0.32% | 359 | 11 | City |
| Red Bud | 3 | 3,754 | 3,786 | -0.19% | 1,431 | 3 | City |
| Steeleville | 4 | 1,876 | 1,918 | -0.37% | 1,232 | 2 | Village |
| Percy | 5 | 904 | 911 | -0.11% | 922 | 1 | Village |
| Coulterville | 6 | 824 | 829 | -0.12% | 1,448 | 1 | Village |
| Tilden | 7 | 745 | 746 | 0% | 764 | 1 | Village |
| Evansville | 8 | 531 | 543 | -0.38% | 674 | 1 | Village |
| Ellis Grove | 9 | 324 | 325 | 0% | 660 | 0 | Village |
| Baldwin | 10 | 312 | 318 | -0.32% | 468 | 1 | Village |
| Rockwood | 11 | 31 | 32 | -3.13% | 146 | 0 | Village |
| Kaskaskia | 12 | 22 | 22 | 0% | 208 | 0 | Village |
Chester is the largest city in Randolph County, with a population of 6,829.
Kaskaskia is the smallest city in Randolph County, with a population of 22.
There are 12 cities in Randolph County, Illinois.