File:MetroLink_Blue_Line_in_Clayton.jpg · Wikimedia Commons · See Wikimedia Commons
St. Louis County
Sign in to saveAlso known as St Louis County, Missouri, Saint Louis County, St. Louis County, Missouri, St Louis County, Saint Louis County, Missouri, St. Louis County, MO
county in Missouri, United States
Key facts
- Country
- United States
- State
- Missouri
- Founded
- October 1, 1812
- Seat
- Clayton
- Largest city
- Florissant
- County executive
- Sam Page ( D )
- Total
- 523.366 sq mi (1,355.51 km )
- Land
- 507.995 sq mi (1,315.70 km )
- Water
- 15.371 sq mi (39.81 km ) 2.9%
- Estimate 2025
- 990,911
- Density
- 1,943.527/sq mi (750.400/km )
- Time zone
- UTC−6 ( Central )
- Summer dst
- UTC−5 ( CDT )
- Congressional districts
- 1st , 2nd
- Website
- stlouiscountymo.gov
via Wikipedia infobox
Wikidata facts
- Named after
- Louis IX of France
- Country
- United States
- Located in
- Missouri
- Contains
- Clayton
- Capital
- Clayton
- Population
- 1004125
- Area
- 1356
- Shares border with
- Monroe County
- Headquarters
- Clayton
- Official website
- stlouiscountymo.gov
- Image
- Downtown Clayton, MO from Wydown.jpg
- Households
- 409658
Show 12 more facts
- Commons category
- St. Louis County, Missouri
- topic's main category
- Category:St. Louis County, Missouri
- twinned administrative body
- Samara
- inception
- 1812-10-01
- category for people born here
- Category:Births in St. Louis County, Missouri
- category of associated people
- Category:People from St. Louis County, Missouri
- different from
- St. Louis
- water as percent of area
- 2.9
- native label
- St. Louis County
- social media followers
- 18337
- category for people who died here
- Category:Deaths in St. Louis County, Missouri
- per capita income
- 42682
Sources (11)
via Wikidata · CC0
~40 min read
Encyclopedic overview
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, while the largest city is Florissant. 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.
Excerpted from Wikipedia’s “St. Louis County” article, available under the CC BY-SA 4.0 licence.
Gallery (8)
On the map
2 mapped locations