| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Dixon | 1 | 14,365 | 15,349 | -1.49% | 1,516 | 9 | City |
| Amboy | 2 | 2,192 | 2,269 | -0.63% | 364 | 6 | City |
| Ashton | 3 | 922 | 961 | -0.75% | 1,279 | 1 | Village |
| Franklin Grove | 4 | 862 | 895 | -0.69% | 2,072 | 0 | Village |
| Paw Paw | 5 | 792 | 825 | -0.75% | 1,322 | 1 | Village |
| Sublette | 6 | 369 | 378 | -0.54% | 923 | 0 | Village |
| Lee | 7 | 298 | 307 | -0.67% | 1,505 | 0 | Village |
| Compton | 8 | 262 | 270 | -0.76% | 1,588 | 0 | Village |
| Steward | 9 | 221 | 227 | -0.45% | 1,674 | 0 | Village |
| Coleta | 10 | 158 | 163 | -0.63% | 427 | 0 | Village |
| West Brooklyn | 11 | 127 | 131 | -0.78% | 1,351 | 0 | Village |
| Nelson | 12 | 126 | 130 | -0.79% | 353 | 0 | Village |
| Harmon | 13 | 115 | 119 | -0.86% | 528 | 0 | Village |
Dixon is the largest city in Lee County, with a population of 14,365.
Harmon is the smallest city in Lee County, with a population of 115.
There are 13 cities in Lee County, Illinois.