| Name | Mercer County |
| State | Illinois |
| FIPS Code | 17131 |
| County Seat | Aledo |
| Timezone | Central Standard Time (CST) |
| Population (2022) | 16,421 |
| Population Growth Rate(2000-2022) | -4.47% |
| Majority Ethnicity | White 98.88% |
| Public School Majority Ethnicity | White 90% |
| Partisan Voting Index | Republican:+13 |
| Unemployment Rate (January 2025) | 4.9% |
| Area Code(s) | 309 |
| Race/Ethnicity | Percentage of Population (2022) |
|---|---|
| White | 98.88% |
| African American | 0.63% |
| Hispanic | 0% |
| Asian | 0.49% |
| Native American | 0% |
| Hawaiin/Pacific Islander | 0% |
| Race/Ethnicity | Percentage of Public School Students (2023) |
|---|---|
| White | 90.4% |
| African American | 0.72% |
| Hispanic | 4.3% |
| Asian | 0.45% |
| Native American | 0.21% |
| Hawaiin/Pacific Islander | 0.07% |