Chaminade College Preparatory School is an independent, Catholic school, administered by the Marianist Order for boys in grades six through twelve in the Archdiocese of St. Louis. The school is located in Creve Coeur, Missouri.

The Archdiocese of St. Louis is a Latin Church ecclesiastical territory or archdiocese of the Catholic Church that covers the City of St. Louis and the Missouri counties of Franklin, Jefferson, Lincoln, Perry, Saint Charles, Saint Francois, Ste. Genevieve, St. Louis, Warren, and Washington. It is the metropolitan see of the ecclesiastical province containing three suffragan sees: Diocese of Springfield-Cape Girardeau, the Diocese of Jefferson City, and the Diocese of Kansas City-Saint Joseph. It is led by Archbishop, Mitchell Thomas Rozanski, formerly the Bishop of Springfield in Massachusetts.