32 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Sugar Creek | 1 | 6,752 | 6,638 | 0.43% | 185 | 37 | Township |
| Looking Glass | 2 | 6,480 | 6,460 | 0.5% | 129 | 50 | Township |
| Breese | 3 | 5,574 | 5,572 | 0.45% | 149 | 37 | Township |
| Breese | 4 | 4,620 | 4,663 | -0.19% | 1,729 | 3 | City |
| Brookside | 5 | 4,430 | 4,434 | 0.29% | 182 | 24 | Township |
| Carlyle | 6 | 3,810 | 3,822 | 0.37% | 214 | 18 | Township |
| New Baden | 7 | 3,387 | 3,424 | -0.24% | 1,856 | 2 | Village |
| Carlyle | 8 | 3,199 | 3,241 | -0.28% | 934 | 3 | City |
| Trenton | 9 | 2,649 | 2,683 | -0.26% | 1,407 | 2 | City |
| Aviston | 10 | 2,454 | 2,352 | 0.82% | 1,534 | 2 | Village |
| Germantown | 11 | 2,175 | 2,088 | 0.88% | 57 | 38 | Township |
| Wade | 12 | 1,689 | 1,658 | 0.96% | 58 | 29 | Township |
| St. Rose | 13 | 1,473 | 1,441 | 0.75% | 39 | 38 | Township |
| Germantown | 14 | 1,401 | 1,330 | 1.01% | 1,374 | 1 | Village |
| Santa Fe | 15 | 1,226 | 1,199 | 0.91% | 48 | 26 | Township |
| Albers | 16 | 1,120 | 1,133 | -0.27% | 1,129 | 1 | Village |
| Irishtown | 17 | 1,059 | 1,030 | 0.86% | 42 | 25 | Township |
| Central City | 18 | 1,058 | 1,101 | -0.84% | 1,873 | 1 | Village |
| Wamac | 19 | 960 | 985 | -0.52% | 678 | 1 | City |
| Beckemeyer | 20 | 924 | 919 | 0.11% | 1,498 | 1 | Village |
| Lake | 21 | 826 | 818 | 0.85% | 28 | 30 | Township |
| Bartelso | 22 | 641 | 629 | 0.31% | 976 | 1 | Village |
| Damiansville | 23 | 556 | 566 | -0.36% | 676 | 1 | Village |
| Junction City | 24 | 521 | 531 | -0.38% | 762 | 1 | Village |
| Meridian | 25 | 511 | 498 | 0.79% | 14 | 37 | Township |
| St. Rose | 26 | 467 | 459 | 0.21% | 790 | 1 | Village |
| Clement | 27 | 462 | 455 | 0.87% | 25 | 19 | Township |
| Wheatfield | 28 | 453 | 443 | 0.89% | 13 | 35 | Township |
| Hoffman | 29 | 429 | 436 | -0.46% | 848 | 1 | Village |
| Keyesport | 30 | 402 | 405 | -0.25% | 558 | 1 | Village |
| East Fork | 31 | 368 | 357 | 0.82% | 12 | 32 | Township |
| Huey | 32 | 161 | 164 | -0.62% | 745 | 0 | Village |
Sugar Creek is the largest city in Clinton County, with a population of 6,752.
Huey is the smallest city in Clinton County, with a population of 161.
There are 32 cities in Clinton County, Illinois.