Dardenne Prairie St. Charles CountyMissouri www.dardenneprairie.org Map Population 13,397 (2020)Type CityArea 5.32 sq mi (13.77 km²), 0 sq mi waterGovernment CITY OF DARDENNE PRAIRIEGovernment office 2032 HANLEY RD, O FALLON, MO 63368