13 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Rockwell City | 1 | 2,156 | 2,253 | -0.87% | 512 | 4.21 | City |
| Lake City | 2 | 1,636 | 1,720 | -1.03% | 339 | 4.82 | City |
| Manson | 3 | 1,625 | 1,702 | -0.91% | 501 | 3.24 | City |
| Pomeroy | 4 | 514 | 528 | -0.58% | 251 | 2.05 | City |
| Twin Lakes | 5 | 510 | 308 | 2.41% | 386 | 1.32 | CDP |
| Lohrville | 6 | 364 | 378 | -0.82% | 162 | 2.25 | City |
| Farnhamville | 7 | 363 | 380 | -0.82% | 551 | 0.66 | City |
| Lytton | 8 | 270 | 280 | -0.74% | 1,174 | 0.23 | City |
| Somers | 9 | 120 | 127 | -0.83% | 352 | 0.34 | City |
| Knierim | 10 | 52 | 54 | 0% | 52 | 0.99 | City |
| Rinard | 11 | 34 | 36 | 0% | 34 | 1 | City |
| Jolley | 12 | 29 | 29 | 0% | 333 | 0.09 | City |
| Yetter | 13 | 19 | 19 | 0% | 148 | 0.13 | City |
Rockwell City is the largest city in Calhoun County, with a population of 2,156.
Yetter is the smallest city in Calhoun County.
There are 13 cities in Calhoun County, Iowa.