| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Hamilton | 1 | 1,736 | 1,690 | 0.58% | 1,182 | 1 | City |
| Braymer | 2 | 759 | 739 | 0.4% | 1,284 | 1 | City |
| Polo | 3 | 506 | 512 | -0.39% | 821 | 1 | City |
| Kingston | 4 | 293 | 297 | -0.34% | 565 | 1 | City |
| Kidder | 5 | 284 | 268 | 0% | 706 | 0 | City |
| Breckenridge | 6 | 248 | 255 | -0.8% | 452 | 1 | City |
| Excelsior Estates | 7 | 235 | 219 | 0.86% | 975 | 0 | Village |
| Cowgill | 8 | 172 | 169 | 0% | 720 | 0 | City |
| Elmira | 9 | 40 | 39 | 0% | 548 | 0 | Village |
Hamilton is the largest city in Caldwell County, with a population of 1,736.
Elmira is the smallest city in Caldwell County, with a population of 40.
There are 9 cities in Caldwell County, Missouri.