13 zips
| Zip Code | City | Population ↓ |
|---|---|---|
| 53511 | Beloit | 48,749 |
| 53546 | Janesville | 29,352 |
| 53545 | Janesville | 24,037 |
| 53548 | Janesville | 20,119 |
| 53534 | Edgerton | 12,306 |
| 53563 | Milton | 11,587 |
| 53536 | Evansville | 9,073 |
| 53520 | Brodhead | 6,709 |
| 53525 | Clinton | 4,024 |
| 53576 | Orfordville | 2,359 |
| 53537 | Footville | 871 |
| 53505 | Avalon | 368 |
| 53501 | Afton | 249 |
The data shown reflect ZCTAs from the US Census. As of 2024, there are 13 ZCTAs in Rock County, Wisconsin (US Census).