7 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Savanna | 1 | 2,671 | 2,796 | -0.78% | 1,021 | 3 | City |
| Thomson | 2 | 1,587 | 1,611 | -0.25% | 715 | 2 | Village |
| Lanark | 3 | 1,439 | 1,510 | -0.83% | 1,284 | 1 | City |
| Mount Carroll | 4 | 1,410 | 1,479 | -0.77% | 704 | 2 | City |
| Milledgeville | 5 | 976 | 1,023 | -0.81% | 1,414 | 1 | Village |
| Shannon | 6 | 862 | 799 | 1.29% | 1,788 | 0 | Village |
| Chadwick | 7 | 473 | 482 | -0.21% | 1,521 | 0 | Village |
Savanna is the largest city in Carroll County, with a population of 2,671.
Chadwick is the smallest city in Carroll County, with a population of 473.
There are 7 cities in Carroll County, Illinois.