6 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Hardin | 1 | 778 | 798 | -0.51% | 366 | 2.13 | Village |
| Kampsville | 2 | 293 | 305 | -0.68% | 287 | 1.02 | Village |
| Hardin township | 3 | 184 | 194 | -1.6% | 5 | 37.38 | Township |
| Batchtown | 4 | 159 | 168 | -1.24% | 85 | 1.86 | Village |
| Brussels | 5 | 115 | 120 | -0.86% | 205 | 0.56 | Village |
| Hamburg | 6 | 94 | 98 | -1.05% | 180 | 0.52 | Village |
Hardin is the largest city in Calhoun County, with a population of 778.
Hamburg is the smallest city in Calhoun County.
There are 6 cities in Calhoun County, Illinois.