St. Charles County Flag

St. Charles County

State:
Missouri
County Seat:
Saint Charles

St. Charles County's estimated 2025 population is 422,381 with a growth rate of 0.68% in the past year according to the most recent United States census data. St. Charles County is the 3rd largest county in Missouri. The 2010 population was 361,808 and has seen a growth of 16.74% since that time.

422,381
Total Population
753
Population Density (mi²)
3
Population Rank (State)
2.9K 0.68%
Annual Population Growth

St. Charles County Population

Demographics

Economics and Income Statistics