Archbishop Mitty High School affectionately known as Mitty by its staff, students and alumni is a private Catholic high school located in San Jose, California, United States. The school is named for John Joseph Mitty, the fourth Archbishop of San Francisco. It is one of many Catholic high schools in the Santa Clara Valley. It is the only Diocesan high school in Santa Clara. Construction of the school began in 1963, and when completed, the campus occupied its present 24 acres (9.7 ha).