Duchesne High School is a small, private, coeducational, Catholic high school in St. Charles, Missouri, USA, in the Roman Catholic Archdiocese of Saint Louis. The name commemorates St. Rose Philippine Duchesne, whose pioneering spirit was the driving force behind her missionary work throughout the region. Duchesne is classified as a regional high school by the Archdiocese of St. Louis, which means that certain parishes are "assigned" to this school as the primary areas served.