International School Bangkok
🇹🇭 Bangkok · Founded 1951 · American / IB · Ages 3–18
A long-established, well-resourced American international school — Thailand's first — offering a US curriculum with both AP and IB Diploma pathways on a large self-contained suburban campus. Strong published academic outcomes; premium fees.
Curricula
American, IB
Age range
3–18
Languages of instruction
English
Annual fees
SGD THB 659,000–1,197,000
Enrollment
1,700
Boarding
No (day school)
IB authorised
DP
Accreditations
WASC, CIS, EARCOS, ISAT
Tier Profile
We only tier dimensions backed by a public inspection verdict or verifiable accreditation. Other dimensions show a data flag — never a guessed score.
BrightKey's Assessment
International School Bangkok (ISB) was founded in 1951 on the grounds of the US Embassy as Thailand's first international school, opening with just 50 students. It has since grown into a large, established institution serving approximately 1,700 students from more than 60 nationalities, spanning Pre-Kindergarten (age 3) through Grade 12. The school is non-boarding and occupies a purpose-built campus within the Nichada Thani community in Pakkret, Nonthaburi, on the northern edge of Bangkok — a residential enclave popular with the expatriate community.
Academically, ISB runs a US-based curriculum with globally recognised pathways. High school students choose among the IB Diploma, an ISB Diploma, AP courses, or hybrid pathways. The Early Childhood division is Reggio Emilia-inspired. This dual AP-plus-IB structure gives families genuine choice between two recognised university-entrance routes within one school.
Published outcomes are strong. For the Class of 2025, 95 students earned the IB Diploma with an average of 34 points, 16% scored 40+, and the top score was 44; 34% earned the Bilingual Diploma. The AP programme expanded sharply, with 277 exams completed in 2025 versus 32 in 2024.
Accreditation is the strongest verifiable governance signal: ISB cites both WASC and CIS accreditation, alongside IB authorisation and memberships in EARCOS, IASAS and ISAT. Because Thailand has no public school inspectorate, this dual-accreditation depth is the conservative basis for an A tier.
Why These Ratings?
Inspection & AccreditationA — Excellent
Dual WASC + CIS accreditation (both cited on the official site) plus IB authorisation — the deepest credible signal available. Thailand has no public inspectorate, so the tier reflects accreditation depth — A.
Strengths & Trade-offs
Strengths
- 70+ year track record as Thailand's first international school, with institutional stability and a large ~1,700-student community
- Dual university pathways — both IB Diploma and AP available within one school, plus an ISB Diploma option
- Strong published IB results: Class of 2025 average 34, top score 44, 16% scoring 40+
- Deep accreditation: both WASC and CIS, plus IB authorisation
- Diverse community spanning 60+ nationalities
- Full Pre-K to Grade 12 continuum with a Reggio Emilia-inspired Early Childhood division
Trade-offs
- Premium fees: high-school tuition THB 1,197,000/year plus a THB 260,000 one-time registration fee place ISB at the top of the Bangkok market
- EAL/ESL support is not described on public pages — families needing English-language support cannot verify provision
- Located in Nichada Thani (Pakkret, Nonthaburi), well north of central Bangkok — a commute consideration
- Exact campus size/acreage is not published
- No boarding option, so it serves only families resident in the area
Is It Right For You?
Best For
- ✓Expatriate and internationally mobile families wanting a stable American-curriculum school with US university orientation
- ✓Students who want to choose between IB Diploma and AP routes within a single school
- ✓Families already living in or near the Nichada Thani / northern Bangkok area
- ✓High-achieving students targeting selective North American and global universities
Not Ideal For
- ✕Families seeking a British/Cambridge IGCSE-A Level pathway (not offered)
- ✕Budget-conscious families — fees are at the premium end
- ✕Families based in central/southern Bangkok unwilling to commute north
- ✕Families needing documented EAL/intensive English support (not verifiable publicly — confirm directly)
Curriculum
US-based curriculum across all divisions. High school offers IB Diploma, ISB Diploma, AP courses, or hybrid pathways. Early Childhood is Reggio Emilia-inspired. Not a Cambridge school.
Fees
2026/27 annual tuition (THB): Pre-Kindergarten 659,000; Elementary (KG–5) 1,015,000; Middle (6–8) 1,137,000; High (9–12) 1,197,000. One-time registration fee THB 260,000; application processing fee THB 4,700; annual fee THB 22,000.
Admissions
Applications run through OpenApply. The site publishes application requirements, key dates, tour booking, and a dedicated fee schedule for US Government and United Nations families.
Campus Life
Purpose-built, self-contained campus within the Nichada Thani residential community in Pakkret, Nonthaburi. A separate Environmental Wilderness Campus operates in Petchaburi Province. Active in the IASAS and EARCOS networks.
University Placement
School-reported · not independently verified
School-reported, unverified: ISB reports Class of 2025 matriculation including Stanford, Cornell, UC Berkeley, UCLA, NUS, UCL and University of Toronto. ISB offers AP rather than A-Levels; 277 AP exams were completed in 2025. Figures are school-published and not independently verified.
Sources
Every verifiable fact carries a public source — verify it yourself.
- ISB official homepage (founding 1951, curriculum, campus) · 2026-06
- ISB About — accreditations & memberships · 2026-06
- ISB About ISB — enrollment ~1,700, 60+ nationalities · 2026-06
- ISB Our Performance — IB DP avg 34, AP, university destinations (Class of 2025) · 2026-06
- ISB Fees — 2026/27 tuition schedule (THB) · 2026-06
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