| Name | Jefferson County |
| State | Wisconsin |
| FIPS Code | 55055 |
| County Seat | Jefferson |
| Timezone | Central Daylight Time (CDT) |
| Population (2024) | 85,971 |
| Population Growth Rate(2020-2024) | -0.22% |
| Majority Ethnicity | White 89.51% |
| Public School Majority Ethnicity | White 76% |
| Partisan Voting Index | Republican:+9 |
| Unemployment Rate (May 2026) | 3.9% |
| Sales Tax Rate (2025) | 5.5% |
| Area Code(s) | 274 / 920 / 262 / 608 |
| Race/Ethnicity | Percentage of Population (2023) |
|---|---|
| White | 89.51% |
| African American | 1.13% |
| Hispanic | 8.34% |
| Asian | 0.61% |
| Native American | 0.31% |
| Hawaiin/Pacific Islander | 0.11% |
| Race/Ethnicity | Percentage of Public School Students (2023) |
|---|---|
| White | 76% |
| African American | 1.49% |
| Hispanic | 17.82% |
| Asian | 1% |
| Native American | 0.15% |
| Hawaiin/Pacific Islander | 0.07% |