St. Mary's High School (St. Louis)

St. Mary's High School is a private, Catholic, all-boys high school located in St. Louis, Missouri. It is administered by the Marianist Province of the United States. The school's history dates back to 1818 when it began as a parish school. It is one of the oldest high schools in the St. Louis area.

St. Mary's offers a college preparatory curriculum. A variety of extracurricular activities are available to students, including athletics, clubs, and organizations. The school's athletic teams compete in the Metro Catholic Conference.

The campus is located in the Dutchtown neighborhood of South St. Louis. The school's mascot is the Dragon. St. Mary's has a strong alumni network and a long tradition of Catholic education in the region.