How to get into Castilleja School
Palo Alto, CA Grades 6–12 · DayMost selective
Castilleja School is a most selective day school in Palo Alto, CA, serving grades 6–12. Applicants typically take the ISEE or SSAT. Below is the admission test, the application timeline, and how to prepare.
Tuition: varies by grade and program. This figure is approximate and changes every year — always confirm current tuition and financial aid on Castilleja School's official site.
Required admission tests
ISEE — Independent School Entrance Exam
Grades 2–12 (Primary / Lower / Middle / Upper) · Stanine 1–9 (no penalty for wrong answers)
Prep for the ISEE with iPrepGeniusSSAT — Secondary School Admission Test
Grades 3–11 (Elementary / Middle / Upper) · Percentile vs. same-grade applicants; penalty for wrong answers (guess wisely)
Prep for the SSAT with iPrepGeniusApplication deadlines
These are typical windows that change each year — confirm current dates on Castilleja School's official admissions page.
How to prepare
- Start with a free diagnostic to find your child's strengths and gaps on the ISEE or SSAT.
- Practice every section with adaptive, verified questions.
- Take full-length, section-timed simulations to build pacing and stamina.
- Track a readiness percentile and follow a weekly study plan up to the deadline.
Build your Castilleja prep plan
Diagnostic → adaptive practice → simulations → readiness score. Start free.
Start freeiPrepGenius is an independent study resource, not affiliated with or endorsed by Castilleja School or any test publisher. School details are a starting guide — verify current requirements with the school.