St Louis County, Missouri

St Louis County, Missouri, was settled by French Colonists in the late 1700’s – today, the population of St. Louis County is greater than that of St. Louis City.

St Louis County, Missouri, was founded by French colonists in the late 1700s.  Once part of the City of St. Louis, the county residents voted in 1877 to separate from St. Louis City.  As a result, the County’s growth increased with a population surpassing St. Louis City in the 1960s.  As a result, efforts have been made to combine the County with St. Louis City multiple times throughout the years, with the most recent proposal in 2019.

St Louis County covers approximately 523 square miles with an estimated population of 998,000 based on the 2010 census.  The county seat is Clayton, Missouri.

Multiple St. Louis County Locations:

Main Location
41 South Central Avenue
Clayton, MO 63105
(314) 615-5000

North County
The Crossings At Northwest
Northwest Crossing
715 Northwest Plaza Drive
St. Ann, MO 63074
(314) 615-5000

West County
Clarkson Wilson Centre
82 Clarkson Wilson Centre
Chesterfield, MO 63017
(314) 615-5000

South County
Keller Plaza
4544 Lemay Ferry Road
St. Louis, MO 63129
(314) 615-5000


  1. St. Louis County, Missouri –
  2. St. Louis, Missouri –
  3. State of Missouri – STL.News
  4. Missouri Resources – STL.News
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