15 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Lawrence township | 1 | 6,160 | 6,183 | 0.23% | 147 | 41.90 | Township |
| Lawrenceville | 2 | 4,288 | 4,180 | 0.52% | 1,982 | 2.16 | City |
| Christy township | 3 | 3,058 | 3,139 | -0.29% | 91 | 33.78 | Township |
| Sumner | 4 | 2,570 | 2,635 | -0.5% | 1,838 | 1.40 | City |
| Bridgeport township | 5 | 2,123 | 2,315 | -1.44% | 133 | 15.94 | Township |
| Bridgeport | 6 | 1,638 | 1,802 | -1.97% | 1,528 | 1.07 | City |
| Denison township | 7 | 1,232 | 1,353 | -1.6% | 21 | 57.90 | Township |
| Sumner township | 8 | 812 | 831 | -0.25% | 22 | 37.25 | Township |
| Petty township | 9 | 577 | 633 | -1.54% | 10 | 57.34 | Township |
| Bond township | 10 | 532 | 583 | -1.66% | 15 | 35.39 | Township |
| St. Francisville | 11 | 510 | 567 | -2.11% | 685 | 0.74 | City |
| Sumner township | 12 | 470 | 500 | -1.05% | 13 | 37.09 | Township |
| Lukin township | 13 | 379 | 414 | -1.56% | 8 | 49.51 | Township |
| Allison township | 14 | 241 | 257 | -0.82% | 5 | 44.53 | Township |
| Russellville | 15 | 86 | 96 | -2.27% | 215 | 0.40 | Village |
Lawrence township is the largest city in Lawrence County, with a population of 6,160.
Russellville is the smallest city in Lawrence County.
There are 15 cities in Lawrence County, Illinois.