Florissant ( (listen)) is a city in St. Louis County, Missouri, within Greater St. Louis. It is a middle class, second-ring northern suburb of St. Louis. Based on 2019 U.S. Census Bureau estimates, the city had a total population of 50,952, making it the 13th-largest city in Missouri and the largest municipality in St. Louis County.
The exact date the first settlers went to the Valley of Florissant is unknown, but it is one of the oldest settlements in the state of Missouri. Some historians believe it was settled about the same time as St. Louis.