9 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Webster City | 1 | 7,736 | 7,816 | -0.17% | 841 | 9 | City |
| Jewell Junction | 2 | 1,245 | 1,211 | 0.48% | 322 | 4 | City |
| Stratford | 3 | 681 | 702 | -0.44% | 375 | 2 | City |
| Ellsworth | 4 | 489 | 506 | -0.61% | 554 | 1 | City |
| Stanhope | 5 | 350 | 362 | -0.57% | 357 | 1 | City |
| Williams | 6 | 295 | 306 | -0.67% | 347 | 1 | City |
| Kamrar | 7 | 176 | 182 | -0.56% | 206 | 1 | City |
| Blairsburg | 8 | 175 | 174 | 0% | 273 | 1 | City |
| Randall | 9 | 156 | 155 | 0% | 385 | 0 | City |
Webster City is the largest city in Hamilton County, with a population of 7,736.
Randall is the smallest city in Hamilton County, with a population of 156.
There are 9 cities in Hamilton County, Iowa.