10 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Parkersburg | 1 | 1,962 | 2,014 | -0.51% | 1,356 | 1.45 | City |
| Shell Rock | 2 | 1,274 | 1,268 | 0.08% | 795 | 1.60 | City |
| Clarksville | 3 | 1,231 | 1,261 | -0.48% | 940 | 1.31 | City |
| Aplington | 4 | 1,074 | 1,111 | -0.65% | 1,461 | 0.73 | City |
| Greene | 5 | 966 | 993 | -0.52% | 847 | 1.14 | City |
| Allison | 6 | 925 | 967 | -0.86% | 316 | 2.93 | City |
| Dumont | 7 | 606 | 636 | -0.98% | 346 | 1.75 | City |
| New Hartford | 8 | 546 | 571 | -0.91% | 881 | 0.62 | City |
| Bristow | 9 | 135 | 144 | -1.46% | 144 | 0.94 | City |
| Aredale | 10 | 58 | 60 | 0% | 58 | 1 | City |
Parkersburg is the largest city in Butler County, with a population of 1,962.
Aredale is the smallest city in Butler County.
There are 10 cities in Butler County, Iowa.