7 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Ottumwa | 1 | 25,742 | 25,459 | 0.18% | 1,602 | 16 | City |
| Eddyville | 2 | 964 | 966 | 0% | 840 | 1 | City |
| Eldon | 3 | 789 | 785 | 0.13% | 721 | 1 | City |
| Agency | 4 | 627 | 615 | 0.32% | 1,108 | 1 | City |
| Blakesburg | 5 | 273 | 272 | 0% | 1,007 | 0 | City |
| Kirkville | 6 | 161 | 155 | 0.63% | 286 | 1 | City |
| Chillicothe | 7 | 80 | 76 | 1.27% | 354 | 0 | City |
Ottumwa is the largest city in Wapello County, with a population of 25,742.
Chillicothe is the smallest city in Wapello County, with a population of 80.
There are 7 cities in Wapello County, Iowa.