St. Louis County, Missouri
Saint Louis County | |
|---|---|
Clayton, the St. Louis County seat | |
Location within the U.S. state of Missouri | |
Missouri's location within the U.S. | |
| Coordinates: 38°38′26.477″N 90°26′45.862″W / 38.64068806°N 90.44607278°W | |
| Country | United States |
| State | Missouri |
| Founded | October 1, 1812 |
| Seat | Clayton |
| Largest city | Florissant |
| Government | |
| • County executive | Sam Page (D) |
| Area | |
• Total | 523.366 sq mi (1,355.51 km2) |
| • Land | 507.995 sq mi (1,315.70 km2) |
| • Water | 15.371 sq mi (39.81 km2) 2.9% |
| Population (2020) | |
• Total | 1,004,125 |
• Estimate (2023) | 987,059 |
| • Density | 1,943.527/sq mi (750.400/km2) |
| Time zone | UTC−6 (Central) |
| • Summer (DST) | UTC−5 (CDT) |
| Congressional districts | 1st, 2nd |
| Website | stlouiscountymo.gov |
St. Louis County is located in eastern Missouri. It is bounded by the City of St. Louis and the Mississippi River to the east, the Missouri River to the north, and the Meramec River to the south. As of the 2020 census, the population was 1,004,125, making it the most populous county in Missouri, and was estimated to be 987,059 in 2023. Its county seat is Clayton. The county is included in the St. Louis, MO–IL metropolitan statistical area.
After Great Britain took over former French territory east of the Mississippi River, many ethnic French colonists moved west. They settled the area of St. Louis County and founded the city of St. Louis in the late 1700s. The US acquired this territory in 1803 with the Louisiana Purchase.
In 1877 residents of the City of St. Louis voted to separate from the county and become an independent city. In the 1960s, with growing suburban development of Greater St. Louis, the county's population overtook that of the city for the first time. Restructuring of industry resulted in job and population declines in the city, and the county has continued to expand.
Through the decades changing conditions have led many business and political leaders to propose merging the city and county as a single government. In 2019, efforts to put the issue to a statewide vote failed to get on a ballot.