7 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Ottumwa | 1 | 25,116 | 25,455 | -0.27% | 1,563 | 16.06 | City |
| Eddyville | 2 | 951 | 968 | -0.31% | 828 | 1.15 | City |
| Eldon | 3 | 771 | 785 | -0.39% | 705 | 1.09 | City |
| Agency | 4 | 613 | 615 | 0% | 1,083 | 0.57 | City |
| Blakesburg | 5 | 267 | 272 | -0.37% | 985 | 0.27 | City |
| Kirkville | 6 | 157 | 156 | 0% | 279 | 0.56 | City |
| Chillicothe | 7 | 79 | 76 | 1.28% | 350 | 0.23 | City |
Ottumwa is the largest city in Wapello County, with a population of 25,116.
Chillicothe is the smallest city in Wapello County.
There are 7 cities in Wapello County, Iowa.