Westridge School is accredited by the Western Association of Schools and Colleges (WASC), and the California Association of Independent Schools.

Westridge is a member of the organizations:

• The National Association of Independent Schools

• The National Coalition of Girls' Schools

• The College Board

• The National Association for College Admission Counseling

• The National Association of Principals of Schools for Girls

• A Better Chance, Inc.

• The Cum Laude Society

• Council for Spiritual and Ethical Education, and the Independent School Alliance for Minority Affairs