International School Bangkok (ISB)

The short version

The short version

International School Bangkok is Thailand’s oldest international school — founded in 1951 and the first in the country to offer the IB Diploma. It is a non-profit teaching roughly 1,800 students from over 60 nationalities on a 37-acre campus inside Nichada Thani, a gated community in Pak Kret, Nonthaburi.

The programme is American at its core, with three graduation pathways: the IB Diploma, the AP Capstone Diploma, and ISB’s own US diploma.↗↗

For an expat family, the practical summary is this: ISB is Bangkok’s American school and its campus-village proposition — the one place in the city where the school run can be a bicycle ride.

Everything about the decision reduces to geography: if you will live in or near Nichada, ISB makes complete sense; if your life is anchored to Sukhumvit or Sathorn, the commute will define your family’s days. Solve location first, then the school.

What the school is

A 1951 pioneer with three ways to graduate

ISB predates the Thai international-school market it now anchors: founded in 1951 for the children of the UN and diplomatic community, it became the first school in Thailand to offer the IB Diploma and remains non-profit and WASC-accredited — satisfying Thailand’s rule that every international school hold recognised overseas accreditation by its fifth year, several decades over.↗↗

The three-pathway structure is the academic signature. Students can graduate via the full IB Diploma (about 55% of the Class of 2026 chose it), the AP Capstone Diploma built on Advanced Placement courses, or the ISB Personal Choice Diploma — the school’s US high school diploma with electives.

For US-bound families this mirrors an American high school; for globally mobile families the IB track keeps every option open.↗

The published outcomes are strong on both tracks. The Class of 2025: 95 IB Diplomas at a 34-point average against a 30.58 global average, 16% at 40+, a top score of 44, and 34% earning bilingual diplomas across eight languages; AP scores averaged 4.13 with 75% of scores at 4 or above.

Recent destinations include Stanford, Cornell, Brown, Penn, Berkeley, UCLA and Imperial, with established pipelines to Japan’s top universities for returning families.↗↗

Fees and the real cost

2025/26 fees — and Bangkok’s widest bus-fee spread

ISB’s 2025/26 tuition, as quoted by Thailand’s Board of Investment from the school’s schedule, is THB 640,000 in Pre-K, THB 985,000 in elementary, THB 1,104,000 in middle school and THB 1,162,000 in high school, plus a THB 260,000 registration fee. A first year including the registration fee reaches roughly THB 946,000–1.48 million depending on grade.

The 2026/27 schedule was not published at research time — confirm with admissions.↗↗

The line that reveals ISB’s geography is the bus fee: distance-banded at THB 108,000–172,800 per child per year — the widest spread among Bangkok’s tier-one schools, because routes run from Nichada across the entire city.

A family busing two children from Sukhumvit can add over THB 300,000 a year to the bill, which is precisely why the live-in-Nichada calculation so often wins.↗

Admissions

Three applicant tracks and a transfer-cycle rhythm

ISB runs separate application tracks for Thai-national, dual-national and expatriate applicants — a structure worth asking about early, because track affects both timing and documentation. Admission weighs academic records, teacher recommendations and assessment; the school frames its process around fit and support rather than selectivity for its own sake.↗↗

The admissions rhythm follows diplomatic and corporate transfer cycles, with August the largest intake and meaningful mid-year movement as postings rotate. ISB’s long experience with arriving-and-departing families shows in its transition support — one practical reason the corporate-transfer community gravitates there.

If your posting confirms late, ask specifically about mid-year entry in your child’s grade.↗

The family experience

Nichada Thani: the compound life ISB is really selling

The 37-acre campus sits inside Nichada Thani, a 395-acre gated community with its own supermarket, cafés, medical clinic and lake, where many ISB families live and children walk or bike to school — a pattern no central-Bangkok school can offer.

The school extends to a 15-acre Environmental Wilderness Campus in Phetchaburi for residential outdoor education, and facilities include an Olympic-sized pool plus a 25-metre pool, five gymnasiums, 12 tennis courts, a baseball field, a climbing wall and a golf centre.↗

The trade-off is explicit even in the school’s own communications: Nichada is roughly 30–60 minutes from Bangkok’s central business districts depending on traffic, and parents who have done both describe Friday afternoon traffic from a central job as the recurring grumble.

Families who choose ISB and live inside Nichada report a small-town rhythm unusual in a megacity; families who try to split the difference with a central home report a commute that wears. The honest advice from the parent community is to decide which of those two families you are before you apply.↗↗

Take these to the school

Questions that move beyond the tour script