37 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Shelbyville | 1 | 4,498 | 4,653 | -0.68% | 1,101 | 4 | City |
| Shelbyville | 2 | 4,322 | 4,484 | -0.85% | 127 | 34 | Township |
| Lakewood | 3 | 4,267 | 4,267 | 0% | 930 | 5 | Village |
| Rose | 4 | 1,848 | 1,912 | -0.81% | 52 | 35 | Township |
| Windsor | 5 | 1,329 | 1,379 | -0.75% | 46 | 29 | Township |
| Prairie | 6 | 1,185 | 1,208 | -0.67% | 22 | 54 | Township |
| Windsor | 7 | 1,028 | 1,068 | -0.77% | 1,632 | 1 | City |
| Tower Hill | 8 | 951 | 968 | -0.21% | 27 | 35 | Township |
| Dry Point | 9 | 928 | 956 | -0.64% | 39 | 24 | Township |
| Okaw | 10 | 868 | 894 | -0.57% | 28 | 31 | Township |
| Richland | 11 | 774 | 807 | -0.9% | 21 | 36 | Township |
| Oconee | 12 | 766 | 786 | -0.52% | 14 | 55 | Township |
| Stewardson | 13 | 719 | 718 | 0% | 1,173 | 1 | Village |
| Sigel | 14 | 703 | 721 | -0.57% | 30 | 24 | Township |
| Windsor | 15 | 656 | 665 | -0.3% | 1,498 | 0 | Village |
| Findlay | 16 | 641 | 668 | -0.77% | 694 | 1 | Village |
| Big Spring | 17 | 600 | 615 | -0.5% | 20 | 29 | Township |
| Herrick | 18 | 524 | 543 | -0.95% | 30 | 17 | Township |
| Strasburg | 19 | 507 | 532 | -0.98% | 937 | 1 | Village |
| Cowden | 20 | 493 | 513 | -0.8% | 1,226 | 0 | Village |
| Tower Hill | 21 | 470 | 482 | -0.42% | 468 | 1 | Village |
| Todds Point | 22 | 450 | 470 | -0.88% | 24 | 19 | Township |
| Ash Grove | 23 | 406 | 413 | -0.25% | 10 | 42 | Township |
| Ridge | 24 | 405 | 412 | -0.25% | 11 | 35 | Township |
| Flat Branch | 25 | 399 | 415 | -0.99% | 12 | 34 | Township |
| Holland | 26 | 379 | 392 | -0.79% | 14 | 27 | Township |
| Lakewood | 27 | 378 | 391 | -1.05% | 13 | 30 | Township |
| Herrick | 28 | 352 | 361 | -0.56% | 962 | 0 | Village |
| Clarksburg | 29 | 349 | 360 | -0.85% | 13 | 27 | Township |
| Cold Spring | 30 | 315 | 323 | -0.63% | 9 | 35 | Township |
| Sigel | 31 | 312 | 322 | -0.64% | 1,110 | 0 | Town |
| Rural | 32 | 309 | 312 | 0% | 9 | 35 | Township |
| Pickaway | 33 | 145 | 154 | -2.03% | 5 | 30 | Township |
| Oconee | 34 | 136 | 141 | -0.73% | 382 | 0 | Village |
| Penn | 35 | 85 | 87 | 0% | 4 | 24 | Township |
| Lakewood | 36 | 24 | 32 | 9.09% | 60 | 0 | CDP |
| Westervelt | 37 | 3 | 33 | -72.73% | 35 | 0 | CDP |
Shelbyville is the largest city in Shelby County, with a population of 4,498.
Westervelt is the smallest city in Shelby County, with a population of 3.
There are 37 cities in Shelby County, Illinois.