| Name | Mercer County |
| State | Illinois |
| FIPS Code | 17131 |
| County Seat | Aledo |
| Timezone | Central Daylight Time (CDT) |
| Population (2024) | 15,456 |
| Population Growth Rate(2020-2024) | -1.55% |
| Majority Ethnicity | White 95.68% |
| Public School Majority Ethnicity | White 90% |
| Partisan Voting Index | Republican:+13 |
| Unemployment Rate (May 2026) | 6.2% |
| Sales Tax Rate (2025) | 7.25% |
| Area Code(s) | 309 |
| Race/Ethnicity | Percentage of Population (2023) |
|---|---|
| White | 95.68% |
| African American | 0.57% |
| Hispanic | 3.32% |
| Asian | 0.34% |
| Native American | 0.09% |
| 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% |