St. Charles County, Missouri

county in Missouri, United States

St. Charles County is a county in Missouri, United States. The county seat is St. Charles. In 2010, 360,485 people lived there, making it the third-most populous county in Missouri.

St. Charles County in Missouri
The flag of St. Charles County, Missouri

St. Charles County is part of the St. Louis, MO-IL Metropolitan Statistical Area and has many of the city's northwestern suburbs.