| Name | Rock County |
| State | Wisconsin |
| FIPS Code | 55105 |
| County Seat | Janesville |
| Timezone | Central Daylight Time (CDT) |
| Population (2024) | 164,443 |
| Population Growth Rate(2020-2024) | 0.46% |
| Majority Ethnicity | White 83.77% |
| Public School Majority Ethnicity | White 68% |
| Partisan Voting Index | Democratic:+4 |
| Unemployment Rate (May 2026) | 4.7% |
| Sales Tax Rate (2025) | 5.5% |
| Area Code(s) | 608 / 262 |
| Race/Ethnicity | Percentage of Population (2023) |
|---|---|
| White | 83.77% |
| African American | 4.73% |
| Hispanic | 10.03% |
| Asian | 1.16% |
| Native American | 0.29% |
| Hawaiin/Pacific Islander | 0.02% |
| Race/Ethnicity | Percentage of Public School Students (2023) |
|---|---|
| White | 67.76% |
| African American | 7.07% |
| Hispanic | 16.85% |
| Asian | 1.24% |
| Native American | 0.24% |
| Hawaiin/Pacific Islander | 0.06% |