Founded in 1960 as Marian High School, Mater Dei Catholic High School in Chula Vista relocated to a 48-acre Otay Ranch campus on Mater Dei Drive in 2007, operating under the Diocese of San Diego. The WASC- and NCEA-accredited coeducational program serves grades nine through twelve with 18 Advanced Placement courses, preparing 87 percent of graduates for four-year university enrollment — a pipeline that begins at Southwestern College for transfer-track students. Roughly 1,130 students compete as Crusaders across CIF-sanctioned teams that have captured state championships in volleyball. The campus sports infrastructure supports cross-training partnerships with Alliance Jiu Jitsu Chula Vista for grappling and submission-focused conditioning. The 18-AP curriculum spans sciences, humanities, and world languages, delivered at a 19:1 student-teacher ratio across dedicated STEM labs, a performing arts theater, and competition-grade athletic fields on the 48-acre grounds.