12 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Rockwell City | 1 | 2,151 | 2,253 | -0.78% | 511 | 4 | City |
| Lake City | 2 | 1,626 | 1,716 | -0.91% | 337 | 5 | City |
| Manson | 3 | 1,618 | 1,701 | -0.86% | 499 | 3 | City |
| Pomeroy | 4 | 504 | 524 | -0.59% | 246 | 2 | City |
| Lohrville | 5 | 360 | 378 | -0.83% | 160 | 2 | City |
| Farnhamville | 6 | 356 | 380 | -1.11% | 540 | 1 | City |
| Lytton | 7 | 269 | 284 | -0.74% | 1,170 | 0 | City |
| Somers | 8 | 118 | 126 | -0.84% | 346 | 0 | City |
| Knierim | 9 | 52 | 55 | 0% | 52 | 1 | City |
| Rinard | 10 | 37 | 39 | 0% | 37 | 1 | City |
| Jolley | 11 | 28 | 28 | 0% | 322 | 0 | City |
| Yetter | 12 | 18 | 20 | 0% | 141 | 0 | City |
Rockwell City is the largest city in Calhoun County, with a population of 2,151.
Yetter is the smallest city in Calhoun County, with a population of 18.
There are 12 cities in Calhoun County, Iowa.