St. Louis County Flag

St. Louis County

State:
Missouri
County Seat:
Clayton

St. Louis County's estimated 2025 population is 994,983 with a growth rate of 0.21% in the past year according to the most recent United States census data. St. Louis County is the largest county in Missouri. The 2010 population was 998,846 and has seen a growth of -0.39% since that time.

994,983
Total Population
1,959
Population Density (mi²)
1
Population Rank (State)
2.1K 0.21%
Annual Population Growth

St. Louis County Population

Demographics

Economics and Income Statistics

Sources

  1. City and Town Population Totals: 2020-2024
  2. US Census State Population Estimates - Most recent state estimates from the Census Bureau's Population Estimates Program
  3. US Census County Population Estimates - Most recent county estimates from the Census Bureau's Population Estimates Program
  4. American Community Survey (2009 - 2013)
  5. Census QuickFacts
  6. Historical Populations of States and Counties (1790 - 1990)