16 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Sigourney | 1 | 1,975 | 2,000 | -0.25% | 913 | 2.16 | City |
| Keota | 2 | 892 | 894 | 0% | 1,154 | 0.77 | City |
| Hedrick | 3 | 716 | 731 | -0.42% | 460 | 1.56 | City |
| What Cheer | 4 | 591 | 605 | -0.51% | 478 | 1.24 | City |
| Richland | 5 | 540 | 539 | 0% | 522 | 1.03 | City |
| Delta | 6 | 256 | 261 | -0.39% | 267 | 0.96 | City |
| Keswick | 7 | 236 | 241 | -0.42% | 529 | 0.45 | City |
| Ollie | 8 | 196 | 200 | -0.51% | 197 | 0.99 | City |
| South English | 9 | 196 | 203 | -0.51% | 624 | 0.31 | City |
| Harper | 10 | 115 | 117 | 0% | 1,307 | 0.09 | City |
| Martinsburg | 11 | 108 | 110 | 0% | 289 | 0.37 | City |
| Webster | 12 | 94 | 96 | 0% | 344 | 0.27 | City |
| Kinross | 13 | 76 | 78 | 0% | 402 | 0.19 | City |
| Gibson | 14 | 57 | 59 | 0% | 905 | 0.06 | City |
| Thornburg | 15 | 47 | 47 | 0% | 236 | 0.20 | City |
| Hayesville | 16 | 44 | 44 | 0% | 176 | 0.25 | City |
Sigourney is the largest city in Keokuk County, with a population of 1,975.
Hayesville is the smallest city in Keokuk County.
There are 16 cities in Keokuk County, Iowa.