Marymount International School, London
Key Stats
Annual Fees: US$50K - US$85K
Curriculum: IB
Age Range: 11-18
Students: ~240
Location: Kingston upon Thames, South West London, London
Updated April 2026
In Brief
Marymount is a compelling choice for families who want outstanding IB results in a small, single-sex boarding-capable environment - and who are comfortable with a Kingston location 12 miles from central London. If you need a school in zones 1-2, or a co-educational setting, look elsewhere.
Marymount sits in its own category among London-area international schools: a Catholic girls' day and boarding school founded in 1955, with an IB DP average of 36.82 in 2025 and a 100% pass rate that places it in the top 2% of IB schools worldwide. The school occupies a substantial campus on George Road in Kingston upon Thames, 12 miles south-west of central London - technically in Surrey, but marketed and understood as a London-area school. With around 240 students from 48 nationalities and an average class size of 12, the educational environment is genuinely personalised.
The IB results are the standout fact. An average of 36.82 out of 45 puts Marymount in a different tier from the non-selective IB schools in this guide, and the 2025 cohort saw 43% of students earn the IB Bilingual Diploma - an indicator of genuine multilingual depth. The boarding option adds a dimension most London international schools cannot offer: weekly and full boarding at GBP 64,110 and GBP 66,990 per year respectively. ISI rated the school Excellent at its November 2022 inspection. The school's Catholic ethos is embedded rather than decorative - it shapes pastoral care, school culture, and community events throughout the year.
The practical constraint is location. Kingston upon Thames is not on the London Underground network - the nearest station is Kingston, with rail connections to Waterloo in around 30 minutes. Without the school minibus or private transport, the journey from central or north London is 45-60 minutes each way. Fees are the highest in this guide for day places (GBP 39,540) and boarding adds considerably on top. The school is girls-only (Years 7-13), so families with sons need separate provision. The Catholic identity also means families from non-Catholic backgrounds should visit and consider whether the ethos is genuinely a good fit.
What parents value
- –IB DP average of 36.82 in 2025 with a 100% pass rate - top 2% of IB schools worldwide. Forty-three percent of 2025 graduates earned the IB Bilingual Diploma. These are among the strongest academic results of any international school in this guide.
- –Average class size of 12 and a total enrolment of around 240 students mean a level of individual attention that is simply not achievable at larger institutions. ISI inspection rated the school Excellent in November 2022.
- –Boarding option (weekly and full) gives families with accommodation constraints, or those relocating intermittently, flexibility that day schools cannot provide. The campus - a purpose-built school on a dedicated site - offers sports, arts, and social facilities that central London schools can only approximate.
Points of consideration
- –Kingston upon Thames is 12 miles from central London and not on the Underground. The daily journey from zones 1-2 is 45-60 minutes each way by rail or road. Map your family's journey in detail before applying.
- –Girls only (Years 7-13). Families with sons, or families where co-education is a priority, will need to look at other schools in this guide.
- –The Catholic ethos shapes school life throughout the year - assemblies, feast days, pastoral structures, and community service. Families from non-Catholic backgrounds are welcome but should visit and experience the culture before applying rather than treating the faith dimension as incidental.
Annual Fees
| Year Group | Age | USDTotal Annual Fee |
|---|---|---|
| Day student (MYP and DP) | 11 | 52,267 |
| Weekly boarding (MYP and DP) | 11 | 84,746 |
| Full boarding (MYP and DP) | 11 | 88,553 |
Fees converted from GBP. For the most up to date and accurate figures please double check with the school.
Additional Fees
| Fee | Amount |
|---|---|
| Application fee (non-refundable) | 317 |
| Acceptance fee (non-refundable) | 3,966 |
| Refundable deposit | 991 |
Academic Results
| IB DP average (2025) | 36.82 |
| IB DP pass rate (2025) | 100% |
| Bilingual Diploma holders (2025) | 43% |
| IB world ranking | Top 2% |
Marymount offers IB MYP (Years 7-11) and IB DP (Years 12-13). There are no GCSEs - the MYP leads directly to the Diploma. The 2025 DP cohort averaged 36.82, making Marymount one of the highest-performing IB schools in the UK. The 43% Bilingual Diploma rate reflects the school's multilingual student body and the school's commitment to language development.
University destinations include leading UK, US, and European institutions. With a small cohort and high results, university counselling is individual in a way that larger schools cannot replicate. Students aiming for competitive US and UK universities are well-supported through the Diploma pathway.
Extra Curriculars
Facilities: Dedicated campus on George Road, Kingston upon Thames KT2 7PE · Sports facilities including netball and tennis courts · Performing arts spaces - theatre, music rooms · Boarding accommodation for weekly and full boarders · Chapel and pastoral common areas
The campus gives students dedicated outdoor space and facilities that central London schools cannot provide. Sport, music, drama, and community service are central to the school's co-curricular offer, with the Catholic ethos shaping how service and leadership are woven into school life.
Boarding adds a residential dimension to school life - boarders and day girls mix in activities, and the relatively small total of 240 students means social divisions between day and boarding communities are less pronounced than at larger boarding schools.
Inspections & Accreditations
Inspection
Latest review: November 2022
Inspection body: ISI
Rating: Excellent
ISI inspected Marymount International School London in November 2022 and rated the school Excellent, confirming it meets all Independent School Standards.
Accreditations
Accreditation details are not publicly listed.
Memberships
Membership details are not publicly listed.
Student Body
Around 240 girls from 48 nationalities, with a roughly even split between day pupils and boarders. The small community creates a close-knit environment where students across year groups know each other well - something the school's Catholic ethos reinforces through shared pastoral and community activities.
No single dominant nationality - the school draws from across London's international community and from boarding families in the UK and internationally. The Catholic identity creates a shared framework that parents describe as providing genuine community cohesion.
Leadership
Margaret Giblin
Margaret Giblin is Headmistress of Marymount International School London, a Catholic girls' school founded in 1955 by the Religious of the Sacred Heart of Mary. She leads a school of around 240 students offering IB MYP and Diploma to girls aged 11-18.