| Name | Piatt County |
| State | Illinois |
| FIPS Code | 17147 |
| County Seat | Monticello |
| Timezone | Central Daylight Time (CDT) |
| Population (2024) | 16,720 |
| Population Growth Rate(2020-2024) | 0.25% |
| Majority Ethnicity | White 96.55% |
| Public School Majority Ethnicity | White 93% |
| Partisan Voting Index | Republican:+16 |
| Unemployment Rate (May 2026) | 4.4% |
| Sales Tax Rate (2025) | 7.25% |
| Area Code(s) | 217 / 309 |
| Race/Ethnicity | Percentage of Population (2023) |
|---|---|
| White | 96.55% |
| African American | 1.61% |
| Hispanic | 1.58% |
| Asian | 0.19% |
| Native American | 0.07% |
| Hawaiin/Pacific Islander | 0% |
| Race/Ethnicity | Percentage of Public School Students (2023) |
|---|---|
| White | 92.71% |
| African American | 1.46% |
| Hispanic | 1.91% |
| Asian | 0.75% |
| Native American | 0.04% |
| Hawaiin/Pacific Islander | 0.04% |