| Place Name | Janesville |
| Place Type | City |
| ZIP Code(s) | 53545 53546 53548 |
| County | Rock County |
| Area Code(s) | 608 |
| Timezone | Central Daylight Time (CDT) |
| Population (2022) | 63,586 |
| Population Growth Rate (2010-19) | 3.21% |
| Majority Ethnicity | White 89.41% |
| Metro/Micro Stats Area | Janesville-Beloit, WI |
| US Congressional District(s) | Wisconsin 1st |
| State Assembly Districts | 31,44 |
| State Senate Districts | 11,15 |
| Race/Ethnicy | Percentage of Population (2021) |
|---|---|
| White | 89.41% |
| African American | 3.01% |
| Hispanic | 0.15% |
| Asian | 1.68% |
| Native American | 0.01% |
| Hawaiin/Pacific Islander | 5.74% |