12 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Rockwell City | 1 | 2,168 | 2,253 | -0.78% | 515 | 4 | City |
| Lake City | 2 | 1,641 | 1,716 | -0.91% | 340 | 5 | City |
| Manson | 3 | 1,632 | 1,701 | -0.85% | 503 | 3 | City |
| Pomeroy | 4 | 507 | 524 | -0.78% | 247 | 2 | City |
| Lohrville | 5 | 363 | 378 | -0.82% | 161 | 2 | City |
| Farnhamville | 6 | 360 | 380 | -1.1% | 546 | 1 | City |
| Lytton | 7 | 271 | 284 | -1.09% | 1,178 | 0 | City |
| Somers | 8 | 119 | 126 | -1.65% | 349 | 0 | City |
| Knierim | 9 | 52 | 55 | -1.89% | 52 | 1 | City |
| Rinard | 10 | 37 | 39 | -2.63% | 37 | 1 | City |
| Jolley | 11 | 28 | 28 | 0% | 322 | 0 | City |
| Yetter | 12 | 18 | 20 | -5.26% | 141 | 0 | City |
Rockwell City is the largest city in Calhoun County, with a population of 2,168.
Yetter is the smallest city in Calhoun County, with a population of 18.
There are 12 cities in Calhoun County, Iowa.