Castilleja is a highly selective private school in the Bay Area with a competitive admissions process. On average, it accepts about 1 out of every 10 applicants, with most openings available at key entry points such as 6th grade.

According to the 2026 Niche rankings, Castilleja School is ranked #1 Best All-Girls High School in California and #8 Best All-Girls High School in the United States. It is also ranked among the top private college-prep schools nationwide due to its strong academics, STEM programs, and college placement outcomes.

Castilleja considers applicants who identify as girls and align with the school’s mission, regardless of sex assigned at birth or gender identity recorded in official documents. The policy is centered on inclusion while maintaining the school’s all-girls educational environment.

Yes, Castilleja accepts international applicants who meet the same admissions requirements as domestic students. Students must demonstrate English proficiency and, if admitted, typically apply for a student visa and live in the Bay Area with a parent or immediate family member.