St. Joseph's Academy is a private, all-girls, Roman Catholic, college preparatory high school in Frontenac, Missouri, a suburb of St.

Mother St. John Fontbonne and the Superior Sisters of St. Joseph were sent from Lyon, France to the territories of Cahokia and Carondelet.

In 1841, Mother Celestine's moved from the log cabin that it had been founded in to a motherhouse in Carondelet, Missouri.

In 1925, the academy moved into Clayton, Missouri along with Fontbonne University.

In 1946, the campus became too small for both the high school and the college, so the academy abandoned the city and moved to Frontenac, Missouri.