| Zip Code | City | Population ↓ |
|---|---|---|
| 50665 | Parkersburg | 2,677 |
| 50670 | Shell Rock | 2,378 |
| 50619 | Clarksville | 2,099 |
| 50636 | Greene | 2,038 |
| 50604 | Aplington | 1,618 |
| 50602 | Allison | 1,382 |
| 50660 | New Hartford | 1,234 |
| 50625 | Dumont | 1,005 |
| 50611 | Bristow | 364 |
| 50608 | Austinville | 43 |
| 50649 | Kesley | 16 |
The data shown reflect ZCTAs from the US Census. As of 2024, there are 11 ZCTAs in Butler County, Iowa (US Census).