There are 171 Fast Food Restaurants in St. Charles County, Missouri, serving a population of 385,115 people in an area of 561 square miles. There is 1 Fast Food Restaurant per 2,252 people, and 1 Fast Food Restaurant per 3 square miles.
In Missouri, St. Charles County is ranked 40th of 115 counties in Fast Food Restaurants per capita, and 4th of 115 counties in Fast Food Restaurants per square mile.