| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Webster City | 1 | 7,820 | 7,812 | 0.06% | 850 | 9 | City |
| Jewell Junction | 2 | 1,246 | 1,210 | 0.65% | 322 | 4 | City |
| Stratford | 3 | 696 | 707 | -0.29% | 383 | 2 | City |
| Ellsworth | 4 | 494 | 506 | -0.4% | 559 | 1 | City |
| Stanhope | 5 | 353 | 363 | -0.56% | 360 | 1 | City |
| Williams | 6 | 301 | 307 | -0.33% | 355 | 1 | City |
| Blairsburg | 7 | 178 | 173 | 0.56% | 277 | 1 | City |
| Kamrar | 8 | 178 | 182 | -0.56% | 208 | 1 | City |
| Randall | 9 | 158 | 154 | 0% | 390 | 0 | City |
Webster City is the largest city in Hamilton County, with a population of 7,820.
Randall is the smallest city in Hamilton County, with a population of 158.
There are 9 cities in Hamilton County, Iowa.