Construction of the school began in 1963, and when completed, the campus occupied its present 24 acres (9.7 ha).

Initially, brothers and priests of the Society of Mary (Marianists) were given responsibility to conduct the school.

As a Catholic college preparatory school, Archbishop Mitty requires coursework in English, mathematics, social studies, science, one of four modern languages (Spanish, French, American Sign Language, and Mandarin Chinese), fine arts, physical education, and religious studies.

The Archbishop Mitty Monarchs field 67 teams in 25 sports, most of them in the West Catholic Athletic League of the CIF Central Coast Section.

Sports include football, badminton, basketball, baseball, cross country, field hockey, golf, soccer, softball, swimming, diving, tennis, track and field, volleyball, water polo, wrestling, and lacrosse.