32 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Sugar Creek | 1 | 6,781 | 6,638 | 0.43% | 186 | 37 | Township |
| Looking Glass | 2 | 6,512 | 6,460 | 0.49% | 129 | 50 | Township |
| Breese | 3 | 5,599 | 5,572 | 0.45% | 150 | 37 | Township |
| Breese | 4 | 4,612 | 4,663 | -0.17% | 1,726 | 3 | City |
| Brookside | 5 | 4,443 | 4,434 | 0.29% | 183 | 24 | Township |
| Carlyle | 6 | 3,824 | 3,822 | 0.37% | 215 | 18 | Township |
| New Baden | 7 | 3,380 | 3,424 | -0.21% | 1,852 | 2 | Village |
| Carlyle | 8 | 3,191 | 3,241 | -0.25% | 932 | 3 | City |
| Trenton | 9 | 2,642 | 2,683 | -0.26% | 1,403 | 2 | City |
| Aviston | 10 | 2,475 | 2,352 | 0.86% | 1,547 | 2 | Village |
| Germantown | 11 | 2,194 | 2,088 | 0.87% | 57 | 38 | Township |
| Wade | 12 | 1,705 | 1,658 | 0.95% | 59 | 29 | Township |
| St. Rose | 13 | 1,484 | 1,441 | 0.75% | 40 | 38 | Township |
| Germantown | 14 | 1,415 | 1,330 | 1% | 1,387 | 1 | Village |
| Santa Fe | 15 | 1,237 | 1,199 | 0.9% | 48 | 26 | Township |
| Albers | 16 | 1,118 | 1,133 | -0.18% | 1,127 | 1 | Village |
| Irishtown | 17 | 1,068 | 1,030 | 0.85% | 43 | 25 | Township |
| Central City | 18 | 1,050 | 1,101 | -0.76% | 1,858 | 1 | Village |
| Wamac | 19 | 955 | 985 | -0.52% | 675 | 1 | City |
| Beckemeyer | 20 | 925 | 919 | 0.11% | 1,499 | 1 | Village |
| Lake | 21 | 833 | 818 | 0.85% | 28 | 30 | Township |
| Bartelso | 22 | 644 | 629 | 0.47% | 980 | 1 | Village |
| Damiansville | 23 | 554 | 566 | -0.36% | 674 | 1 | Village |
| Junction City | 24 | 519 | 531 | -0.38% | 759 | 1 | Village |
| Meridian | 25 | 515 | 498 | 0.78% | 14 | 37 | Township |
| St. Rose | 26 | 469 | 459 | 0.43% | 794 | 1 | Village |
| Clement | 27 | 466 | 455 | 0.87% | 25 | 19 | Township |
| Wheatfield | 28 | 457 | 443 | 0.88% | 13 | 35 | Township |
| Hoffman | 29 | 428 | 436 | -0.23% | 846 | 1 | Village |
| Keyesport | 30 | 402 | 405 | 0% | 558 | 1 | Village |
| East Fork | 31 | 371 | 357 | 0.82% | 12 | 32 | Township |
| Huey | 32 | 161 | 164 | 0% | 745 | 0 | Village |
Sugar Creek is the largest city in Clinton County, with a population of 6,781.
Huey is the smallest city in Clinton County, with a population of 161.
There are 32 cities in Clinton County, Illinois.