| Name | Saint Charles County |
| State | Missouri |
| FIPS Code | 29183 |
| County Seat | St. Charles |
| Timezone | Central Standard Time (CST) |
| Population (2022) | 360,695 |
| Population Growth Rate(2000-2022) | 12.42% |
| Majority Ethnicity | White 91.58% |
| Public School Majority Ethnicity | White 76% |
| Partisan Voting Index | Republican:+9 |
| Unemployment Rate (January 2025) | 2.7% |
| Area Code(s) | 636 / 314 / 557 |
| Race/Ethnicity | Percentage of Population (2022) |
|---|---|
| White | 91.58% |
| African American | 5.33% |
| Hispanic | 0.09% |
| Asian | 2.91% |
| Native American | 0.05% |
| Hawaiin/Pacific Islander | 0.05% |
| Race/Ethnicity | Percentage of Public School Students (2023) |
|---|---|
| White | 75.68% |
| African American | 8.26% |
| Hispanic | 6.51% |
| Asian | 3.44% |
| Native American | 0.16% |
| Hawaiin/Pacific Islander | 0.13% |