| Name | Mason County |
| State | Illinois |
| FIPS Code | 17125 |
| County Seat | Havana |
| Timezone | Central Standard Time (CST) |
| Population (2022) | 14,636 |
| Population Growth Rate(2000-2022) | -10.77% |
| Majority Ethnicity | White 99.11% |
| Public School Majority Ethnicity | White 95% |
| Partisan Voting Index | Strongly Republican:+21 |
| Unemployment Rate (January 2025) | 4.8% |
| Area Code(s) | 309 / 217 |
| Race/Ethnicity | Percentage of Population (2022) |
|---|---|
| White | 99.11% |
| African American | 0.51% |
| Hispanic | 0.06% |
| Asian | 0.31% |
| Native American | 0% |
| Hawaiin/Pacific Islander | 0% |
| Race/Ethnicity | Percentage of Public School Students (2023) |
|---|---|
| White | 94.6% |
| African American | 0.53% |
| Hispanic | 2.11% |
| Asian | 0.33% |
| Native American | 0% |
| Hawaiin/Pacific Islander | 0.07% |