| Area Code | 557 |
| State | Missouri |
| Current Time in Area Code 557 | 557> CDT |
| Timezone | Central Daylight Time |
| Regional Market Area | Metro St. Louis |
| Metro Area(s) | St. Louis, MO-IL |
| Population (2020) | 1305703 |
| Adjacent Area Codes | 314,618,636,730 |
| Overlay Area Codes | 314 |
| Saint Louis City County |
| Saint Louis County |
| Florissant |
| Oakville |
| St. Louis |
| University City |