7 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Ottumwa | 1 | 25,695 | 25,459 | 0.18% | 1,600 | 16 | City |
| Eddyville | 2 | 964 | 966 | -0.1% | 840 | 1 | City |
| Eldon | 3 | 788 | 785 | 0% | 720 | 1 | City |
| Agency | 4 | 625 | 615 | 0.32% | 1,104 | 1 | City |
| Blakesburg | 5 | 273 | 272 | 0% | 1,007 | 0 | City |
| Kirkville | 6 | 160 | 155 | 0.63% | 284 | 1 | City |
| Chillicothe | 7 | 79 | 76 | 0% | 350 | 0 | City |
Ottumwa is the largest city in Wapello County, with a population of 25,695.
Chillicothe is the smallest city in Wapello County, with a population of 79.
There are 7 cities in Wapello County, Iowa.