4 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Dahlgren | 1 | 488 | 503 | -0.41% | 480 | 1 | Village |
| Broughton | 2 | 177 | 183 | -0.56% | 94 | 2 | Village |
| Belle Prairie City | 3 | 45 | 47 | 0% | 103 | 0 | Town |
| Macedonia | 4 | 29 | 29 | 0% | 107 | 0 | Village |
Dahlgren is the largest city in Hamilton County, with a population of 488.
Macedonia is the smallest city in Hamilton County, with a population of 29.
There are 4 cities in Hamilton County, Illinois.