13 zips
| Zip Code | City | Population ↓ |
|---|---|---|
| 53511 | Beloit | 48,305 |
| 53546 | Janesville | 29,482 |
| 53545 | Janesville | 23,937 |
| 53548 | Janesville | 20,509 |
| 53534 | Edgerton | 12,344 |
| 53563 | Milton | 11,468 |
| 53536 | Evansville | 9,449 |
| 53520 | Brodhead | 6,758 |
| 53525 | Clinton | 4,083 |
| 53576 | Orfordville | 2,309 |
| 53537 | Footville | 818 |
| 53505 | Avalon | 370 |
| 53501 | Afton | 147 |
The data shown reflect ZCTAs from the US Census. As of 2024, there are 13 ZCTAs in Rock County, Wisconsin (US Census).