St. Charles County Flag

St. Charles County

State:
Missouri
County Seat:
St Charles

St. Charles County's estimated 2026 population is 430,408 with a growth rate of 0.92% 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 18.96% since that time.

430,408
Total Population
767
Population Density (mi²)
3
Population Rank (State)
3.9K 0.92%
Annual Population Growth

St. Charles County Population

Demographics

Economics and Income Statistics