Legacy, academics and leadership at the oldest independent girls’ school in Southern California.
Cardinal Education is an independent educational consulting company. We are not affiliated, associated, authorized, endorsed by, or in any way officially connected with any public or private school.
In This Guide
Quick Answer for Busy Parents
Marlborough is an independent, all-girls day school for grades 7 through 12 in Hancock Park, founded in 1889 and the oldest independent girls’ school in Southern California. Niche ranks it the number one all-girls high school in the Los Angeles area for 2026 and number two in California. It enrolls 530 students, offers more than 200 courses, and admits without an interview or required test scores.
Where Marlborough Actually Ranks
Rankings deserve a sceptical eye, but they are useful for orientation as long as the numbers are current and correctly stated. Niche’s 2026 figures put Marlborough at the top of the Los Angeles all-girls field and near the top statewide.
| Niche 2026 ranking | Marlborough’s position |
| Best All-Girls High Schools in the Los Angeles Area | 1 of 21 |
| Best All-Girls High Schools in California | 2 of 34 |
| Best All-Girls High Schools in America | 9 |
| Best High Schools for STEM in the Los Angeles Area | 3 of 512 |
| Best Private High Schools in California | 14 of 438 |
| Overall Niche grade | A+ |
Worth stating plainly, because it circulates incorrectly: Marlborough is the top-ranked all-girls high school in the Los Angeles area, not in California. The statewide title belongs to another school. For the wider field, our roundup of the best all-girls private schools in California gives the full picture.
A Legacy That Started in 1889
Mary Caswell, a young teacher from Maine, founded the school as St. Margaret’s School for Girls in 1889. It moved from Pasadena to Los Angeles the following year, took the Marlborough name from the hotel building it occupied, and has been at 250 South Rossmore Avenue in Hancock Park for over a century. That makes it the oldest independent girls’ school in Southern California.
The heritage is visible in ways that still shape a student’s week. The Ring Ceremony, marking the junior class’s passage into senior year, has run since 1933. The Pin Ceremony, marking completion of Middle School in ninth grade, dates to 1961. Students are still called Violets after the school’s original mascot, a name that survives in the student newspaper, The UltraViolet, and in the student-led Violets’ Giving Circle.
Academics: Depth Over Volume
Marlborough offers 17 Advanced Placement courses and 14 Advanced Topics courses, drawn from a catalogue of more than 200 distinct offerings. Seventy percent of faculty hold advanced degrees, the average class runs to 14 students, and the student-faculty ratio is 7:1. The school also belongs to One Schoolhouse, a consortium that supplements its own catalogue.
Above the Advanced Placement layer sit five Signature Programs: the Leonetti/O’Connell Honors Research Program, the Global Futures Institute, Debate, Competitive Robotics and the Frank & Eileen Accelerator Program. Marlborough runs five robotics teams and has earned three world-championship-level awards, and three students were published in academic journals or books during the 2024-25 school year. For families weighing a girls’ school partly on STEM grounds, our piece on women in STEM and the stereotypes that persist is worth reading alongside those numbers.
Leadership, Built Into the Structure
In a school where every student is a girl, every leadership role is held by one. That sounds obvious and it is the entire point. Students serve on the All-School Council, edit The UltraViolet, and run the Violets’ Giving Circle, which has raised $500,000 for Los Angeles organisations. Marlborough sponsors students to attend the Student Diversity Leadership Conference and partners with twelve nonprofit and community organisations across the city through its Social Justice and Community Partnerships department.
Comparing all-girls schools in Los Angeles?
We help families weigh fit against reputation, and we will tell you when a highly ranked school is the wrong one for your daughter.
What Marlborough School Admissions Actually Looks For
Marlborough’s process is shorter than most families expect. Four components go through the Ravenna portal: the initial application, the Character Skills Snapshot, three recommendation forms from a school administrator plus current English and math teachers, and an official transcript. There is no admissions interview and no required ISEE or SSAT score. The deadline for the 2027-28 year is January 8, 2027. Because the file is thin, the Snapshot carries real weight, and our explainer on how schools read Character Skills Snapshot results is the piece most families find useful first.
Entry grades are 7 and 9. Space in grades 8, 10 and 11 is extremely limited, and Marlborough does not admit seniors. Students must live in Los Angeles with a parent or legal guardian. The full walkthrough is in our complete Marlborough admissions guide.
A ranking tells you how a school looks from outside. What should decide the question is whether your daughter, standing on that campus in October, can picture herself arguing a point in a seminar of fourteen. That is a better test than any list.
Ready to talk through fit?
Tell us about your daughter and the schools you are weighing. We will give you an honest read, not a pitch.
Related Articles:
How to Get Into Marlborough School: A Complete Admissions Guide for Parents
Inside Marlborough School Student Life: Clubs, Traditions, and the Equestrian Team