11 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Garner | 1 | 3,021 | 3,055 | -0.23% | 1,422 | 2.13 | City |
| Britt | 2 | 1,982 | 2,036 | -0.55% | 1,479 | 1.34 | City |
| Kanawha | 3 | 630 | 652 | -0.63% | 318 | 1.98 | City |
| Klemme | 4 | 424 | 438 | -0.7% | 848 | 0.50 | City |
| Corwith | 5 | 256 | 266 | -0.78% | 177 | 1.45 | City |
| Crystal Lake | 6 | 238 | 253 | -1.24% | 960 | 0.25 | City |
| Woden | 7 | 178 | 185 | -0.56% | 361 | 0.49 | City |
| Goodell | 8 | 138 | 142 | -0.72% | 319 | 0.43 | City |
| Duncan | 9 | 67 | 102 | -6.94% | 85 | 0.79 | CDP |
| Miller | 10 | 65 | 30 | 6.56% | 31 | 2.06 | CDP |
| Hayfield | 11 | 25 | 56 | 8.7% | 26 | 0.97 | CDP |
Garner is the largest city in Hancock County, with a population of 3,021.
Hayfield is the smallest city in Hancock County.
There are 11 cities in Hancock County, Iowa.