14 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 |
| Lakewood | 2 | 4,267 | 4,267 | 0% | 930 | 4.59 | Village |
| Windsor | 3 | 1,028 | 1,068 | -0.77% | 1,632 | 0.63 | City |
| Stewardson | 4 | 719 | 718 | 0% | 1,173 | 0.61 | Village |
| Windsor | 5 | 656 | 665 | -0.3% | 1,498 | 0.44 | Village |
| Findlay | 6 | 641 | 668 | -0.77% | 694 | 0.92 | Village |
| Strasburg | 7 | 507 | 532 | -0.98% | 937 | 0.54 | Village |
| Cowden | 8 | 493 | 513 | -0.8% | 1,226 | 0.40 | Village |
| Tower Hill | 9 | 470 | 482 | -0.42% | 468 | 1 | Village |
| Herrick | 10 | 352 | 361 | -0.56% | 962 | 0.37 | Village |
| Sigel | 11 | 312 | 322 | -0.64% | 1,110 | 0.28 | Town |
| Oconee | 12 | 136 | 141 | -0.73% | 382 | 0.36 | Village |
| Lakewood | 13 | 24 | 32 | 9.09% | 60 | 0.40 | CDP |
| Westervelt | 14 | 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 14 cities in Shelby County, Illinois.