Saint Mary’s Academy was founded in 1889 and is the oldest continuously operating Catholic high school in the Archdiocese of Los Angeles. It was founded in 1889 by the Sisters of Saint Joseph of Carondelet as a private high school for girls and today is staffed by religious and lay men and women.

When the population of Los Angeles was about fifty thousand, Saint Mary’s enrolled fifty pupils in a parish school on Twenty-First Street near Grand Avenue and on June 28, 1892, the first commencement was held with two graduates. As the city emerged from its “pueblo” days, Saint Mary’s increased in facilities and enrollment. By 1903, the original campus comprised four buildings which provided for both a girls’ high school and a grammar school, a music and art conservatory, the administrative center of the western province of the Sisters of Saint Joseph, and a boys’ school which later became Saint Vincent’s Grammar School.

In 1904, the second site of Saint Mary’s was purchased at Slauson Avenue and what is now Crenshaw Boulevard. When the new building was completed in 1911, cattle still grazed nearby and the twenty acres that comprised the school property were surrounded by truck farms. The new buildings provided accommodations for two hundred boarding students, and classrooms were designed for additional day students. A high school and grammar school were maintained with special provisions for music and art. When more room was needed, two additional halls were added in 1921 and 1922. College classes were inaugurated in 1925 for the future Mount Saint Mary’s College, and a special building was built for them. The high school then offered three diplomas: Latin-Scientific, Academic, and Elective. Special Music diplomas were awarded to four-year pianists, organists, or harpists. Saint Mary’s was accredited to the University of California and to Mount Saint Mary’s College. When the latter was transferred to its present site in the Santa Monica Mountains in 1931, the college building was utilized by the Academy.

The grammar school was closed in 1946 making classroom space available for the increasing high school enrollment. In 1957 student boarding was discontinued.

With future progress in mind and in the hope of continuing to provide a Christian education with the best and most modern facilities, Saint Mary’s again moved in 1966 to the present site in Inglewood. Cherished reminders of the old campus appear on the Inglewood campus. Among these are a statue of Mary, the cornerstone outside the chapel, the stained glass window in the front foyer which bears the school motto and seal, the victory bell in the Quad, and several trees which were transplanted from the Slauson site.

The aim of the Sisters of Saint Joseph of Carondelet and the lay women and men of the faculty at Saint Mary's has always been to educate young women to take an active part as Christians in society. It continues in this tradition to educate and guide young women toward maturity in an ever changing world.