37 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Shelbyville | 1 | 4,498 | 4,653 | -0.68% | 1,101 | 4.08 | City |
| Shelbyville township | 2 | 4,322 | 4,484 | -0.85% | 127 | 34.04 | Township |
| Lakewood | 3 | 4,267 | 4,267 | 0% | 930 | 4.59 | Village |
| Rose township | 4 | 1,848 | 1,912 | -0.81% | 52 | 35.48 | Township |
| Windsor township | 5 | 1,329 | 1,379 | -0.75% | 46 | 28.67 | Township |
| Prairie township | 6 | 1,185 | 1,208 | -0.67% | 22 | 54.16 | Township |
| Windsor | 7 | 1,028 | 1,068 | -0.77% | 1,632 | 0.63 | City |
| Tower Hill township | 8 | 951 | 968 | -0.21% | 27 | 34.83 | Township |
| Dry Point township | 9 | 928 | 956 | -0.64% | 39 | 24.05 | Township |
| Okaw township | 10 | 868 | 894 | -0.57% | 28 | 30.92 | Township |
| Richland township | 11 | 774 | 807 | -0.9% | 21 | 36.32 | Township |
| Oconee township | 12 | 766 | 786 | -0.52% | 14 | 55.09 | Township |
| Stewardson | 13 | 719 | 718 | 0% | 1,173 | 0.61 | Village |
| Sigel township | 14 | 703 | 721 | -0.57% | 30 | 23.83 | Township |
| Windsor | 15 | 656 | 665 | -0.3% | 1,498 | 0.44 | Village |
| Findlay | 16 | 641 | 668 | -0.77% | 694 | 0.92 | Village |
| Big Spring township | 17 | 600 | 615 | -0.5% | 20 | 29.34 | Township |
| Herrick township | 18 | 524 | 543 | -0.95% | 30 | 17.40 | Township |
| Strasburg | 19 | 507 | 532 | -0.98% | 937 | 0.54 | Village |
| Cowden | 20 | 493 | 513 | -0.8% | 1,226 | 0.40 | Village |
| Tower Hill | 21 | 470 | 482 | -0.42% | 468 | 1 | Village |
| Todds Point township | 22 | 450 | 470 | -0.88% | 24 | 19.03 | Township |
| Ash Grove township | 23 | 406 | 413 | -0.25% | 10 | 42.12 | Township |
| Ridge township | 24 | 405 | 412 | -0.25% | 11 | 35.39 | Township |
| Flat Branch township | 25 | 399 | 415 | -0.99% | 12 | 33.77 | Township |
| Holland township | 26 | 379 | 392 | -0.79% | 14 | 26.99 | Township |
| Lakewood township | 27 | 378 | 391 | -1.05% | 13 | 30.08 | Township |
| Herrick | 28 | 352 | 361 | -0.56% | 962 | 0.37 | Village |
| Clarksburg township | 29 | 349 | 360 | -0.85% | 13 | 27.12 | Township |
| Cold Spring township | 30 | 315 | 323 | -0.63% | 9 | 34.95 | Township |
| Sigel | 31 | 312 | 322 | -0.64% | 1,110 | 0.28 | Town |
| Rural township | 32 | 309 | 312 | 0% | 9 | 34.61 | Township |
| Pickaway township | 33 | 145 | 154 | -2.03% | 5 | 29.70 | Township |
| Oconee | 34 | 136 | 141 | -0.73% | 382 | 0.36 | Village |
| Penn township | 35 | 85 | 87 | 0% | 4 | 23.76 | Township |
| Lakewood | 36 | 24 | 32 | 9.09% | 60 | 0.40 | CDP |
| Westervelt | 37 | 3 | 33 | -72.73% | 35 | 0.09 | CDP |
Shelbyville is the largest city in Shelby County, with a population of 4,498.
Westervelt is the smallest city in Shelby County.
There are 37 cities in Shelby County, Illinois.