| Place Name | Affton |
| Place Type | Census Designated Place |
| ZIP Code(s) | 63123 63125 |
| County | Saint Louis County |
| Area Code(s) | 314 |
| Timezone | Central Daylight Time (CDT) |
| Population (2022) | 19,945 |
| Population Growth Rate (2010-19) | 0.54% |
| Majority Ethnicity | White 91.03% |
| Metro/Micro Stats Area | St. Louis, MO-IL |
| US Congressional District(s) | Missouri 2nd |
| State House Districts | 92,94 |
| State Senate Districts | 1 |
| Race/Ethnicy | Percentage of Population (2021) |
|---|---|
| White | 91.03% |
| African American | 3.07% |
| Hispanic | 0.08% |
| Asian | 2.34% |
| Native American | 0% |
| Hawaiin/Pacific Islander | 3.47% |