St. Charles County lies in eastern Missouri in the United States. It is an administrative county whose government is based in the city that serves as its county seat, St. Charles. At the time of the 2010 census the county's population was recorded as 360,485, making it one of the state's most populous counties then.

Metropolitan context

St. Charles County is included in the greater St. Louis MO-IL Metropolitan Statistical Area. Much of the county functions as part of the region's northwestern ring of suburbs, with residential neighborhoods, shopping centers and commuter links that connect to the city of St. Louis.

Characteristics and role

The county combines suburban development with pockets of older towns and open space. Its proximity to the St. Louis metropolitan core has contributed to residential growth, commercial activity and transportation infrastructure that serve both local residents and commuters. County institutions provide services such as public safety, road maintenance and land-use planning for a mixture of urban, suburban and rural areas.

Administration and communities

Local government in the county is responsible for a range of public services and works with municipal governments inside its borders. The city of St. Charles remains the central hub for county administration and courts, while other incorporated and unincorporated places contribute to the county's social and economic life.

Population figures from the 2010 census provide a baseline for understanding the county's size and rank within Missouri; subsequent estimates and later censuses show continued growth in many suburban counties surrounding major metropolitan areas such as St. Louis. Planning documents and demographic reports produced by county and regional agencies are the best sources for updated population counts and projections.