11 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Freeport | 1 | 22,730 | 23,960 | -0.89% | 1,915 | 12 | City |
| Lena | 2 | 2,619 | 2,759 | -0.87% | 988 | 3 | Village |
| Pearl City | 3 | 744 | 780 | -0.8% | 1,152 | 1 | Village |
| Orangeville | 4 | 725 | 766 | -0.96% | 1,069 | 1 | Village |
| Cedarville | 5 | 632 | 670 | -0.94% | 1,371 | 0 | Village |
| Davis | 6 | 557 | 590 | -0.89% | 1,362 | 0 | Village |
| Dakota | 7 | 469 | 499 | -1.05% | 1,884 | 0 | Village |
| German Valley | 8 | 409 | 432 | -0.97% | 880 | 0 | Village |
| Rock City | 9 | 282 | 296 | -0.7% | 2,074 | 0 | Village |
| Winslow | 10 | 264 | 282 | -1.12% | 576 | 0 | Village |
| Ridott | 11 | 121 | 127 | -0.82% | 1,513 | 0 | Village |
Freeport is the largest city in Stephenson County, with a population of 22,730.
Ridott is the smallest city in Stephenson County, with a population of 121.
There are 11 cities in Stephenson County, Illinois.