Founded in 1876, Saint Mary's High School (SMHS) is a co-educational, Roman Catholic, college preparatory school in Stockton, California. The school is under the canonical jurisdiction of the Diocese of Stockton and is sponsored by the Salesian Order of Priests and Brothers of St. Francis de Sales (Province of Toledo–Ohio). The school is a member of the board of the college and is accredited by the Western Schools and Colleges Association and the Western Catholic Education Association.
The roots of St. Mary go back to 1876 when the St. Agnes Academy opened for girls in grades 1–12 as a boarding and a free day-school. The faculty then consisted of seven sisters and 95 students from Dominican countries. St. Mary's development since that beginning has been reflected in the need to move sites five times to its present 25-acre (100,000 m2) site on North El Dorado, Avenue. A separate corporate entity within the Stockton Diocese, St. Mary's is a co-ed high school with a 926 student body and over 110 teachers and support staff.
Throughout its history, St. Mary's high school has a religious presence of priests, brothers, and sisters. The Brothers of Jesus, a number of Franciscan Friars, diocesan priests, the Sisters of the Blessed Virgin Mary and the Oblates of St. Francis de Sales have joined the Dominican Sisters of San Rafael.
At the college, laymen and women helped to improve the program. The college teaches in 10 disciplines and offers over 130 courses in theology, English, social studies, mathematics, physical education, technology, computer tools, foreign languages, business and technical skills, and fine arts. There are 27 co-curricular activities and teams eligible for 15 sports too.
The school is located on North El Dorado Street, 1 mile (1.6 km) east of San Joaquin Delta College and 2 miles (3.2 km) north of the University of the Pacific.
Five classroom buildings, a cafeteria, a student shop, two gymnasiums, a football field, track facilities, and baseball and soccer fields all within the Thompson Sports Complex are situated on 25 acres (10 ha). The priests and brothers affiliated with the Oblates of St. Francis de Sales (Province of Toledo–Ohio) have a house on campus. The Cortopassi Aquatics Center is host to the St. Mary's Aquatic Sports Program, which opened September 2007. The Chase Family Fitness Center is a weight-training facility of 14,000 square feet (1,300 m2) complementing the Sprague Family Athletic Facility.
The registration to the school is normally less than 1,000. Around 81 percent of the student body identifies as Catholic. The faculty consists of 4 religious (Priests, Brothers, and Sisters) and 110 lay teachers and support staff. The student-faculty ratio is 24/1 and the average size of the classroom is 25.