10 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Parkersburg | 1 | 1,979 | 2,014 | -0.35% | 1,368 | 1 | City |
| Shell Rock | 2 | 1,264 | 1,268 | -0.08% | 789 | 2 | City |
| Clarksville | 3 | 1,232 | 1,260 | -0.48% | 941 | 1 | City |
| Aplington | 4 | 1,082 | 1,112 | -0.55% | 1,472 | 1 | City |
| Greene | 5 | 965 | 995 | -0.62% | 846 | 1 | City |
| Allison | 6 | 929 | 966 | -0.85% | 317 | 3 | City |
| Dumont | 7 | 608 | 636 | -0.98% | 348 | 2 | City |
| New Hartford | 8 | 550 | 572 | -0.9% | 887 | 1 | City |
| Bristow | 9 | 137 | 144 | -1.44% | 146 | 1 | City |
| Aredale | 10 | 58 | 60 | -1.69% | 58 | 1 | City |
Parkersburg is the largest city in Butler County, with a population of 1,979.
Aredale is the smallest city in Butler County, with a population of 58.
There are 10 cities in Butler County, Iowa.