St. Louis County Flag

St. Louis County

State:
Missouri
County Seat:
Clayton

St. Louis County's estimated 2025 population is 979,595 with a growth rate of -0.38% in the past year according to the most recent United States census data. St. Louis County is the 1st largest county in Missouri. The 2010 population was 998,846 and has seen a growth of -1.93% since that time.

979,595
Total Population
1,928
Population Density (mi²)
1
Population Rank (State)
-3.7K -0.38%
Annual Population Growth

St. Louis County Population

Demographics

Economics and Income Statistics