Top 10 International Schools in Bangkok (2026)

The brief

NIST, Patana, and ISB are the city's anchors. Full IB at NIST, English National Curriculum into IB Diploma at Patana, American with AP and IB at ISB. Waiting lists run 12 to 18 months at most year groups.
Shrewsbury Riverside and Harrow Bangkok lead the British market with externally inspected A-Level outcomes (*65% to 68% A\/A**) and a real UK independent-school operating model.
King's College Bangkok is the strongest of the newer UK-brand entrants. BSO Outstanding 2024 and *90% A\/A at A-Level**, at small cohort sizes.
Bangkok Prep is the best value through-school with continuous A-Level: *52% A\/A at A-Level** at roughly half the Shrewsbury fee.
Brighton, Concordian, and Bromsgrove round out the ten. Each is the right answer for a specific family, not the default for everyone.

Bangkok runs more than 200 schools that describe themselves as international. The realistic shortlist is closer to a dozen, and three names dominate every conversation: NIST, Bangkok Patana, and International School Bangkok. They sit at the top because they combine four to seven decades of operating history, full three-to-eighteen continuums, three sets of externally inspected results, and the deepest co-curricular benches in the city. The next seven differ on curriculum, location, and design. The strongest school in Bangkok for a four-year-old is not the strongest for a sixteen-year-old; the ranking is ordinal, the question is fit.

Top-tier fees run THB 600,000 to 1.2 million per year (roughly USD 17,000 to 35,000 at THB 35 to USD 1). Mid-tier through-schools sit between USD 8,000 and 23,000, good value by international city standards.

The ranking

1. NIST International School Bangkok

NIST is the only full IB-continuum school in central Bangkok and the only one founded as a not-for-profit by the diplomatic community. The Sukhumvit campus sits inside the BTS catchment on Soi 15 and is the easiest premium school to reach from anywhere along the central expat corridor.

The 2025 IB Diploma cohort posted an average of 37 points, a 100% pass rate, and 28% at 40 or more points against a worldwide average of 9%. Two students scored the full 45. That is the strongest IB performance in the city and one of the strongest in Southeast Asia.

Founded 1992. Pupils around 1,800. Fees THB 628,000 to 1,094,500 (USD 17,800 to 31,100). Accreditation CIS and NEASC. Waiting lists run at most year groups; Pre-K, Year 7, and Year 12 are the realistic entry points.

2. Bangkok Patana School

Patana is the oldest international school in Thailand (1957) and the closest thing Bangkok has to a flagship British international. The 25-acre Sukhumvit 105 campus runs the English National Curriculum from Foundation Stage through Year 11 (IGCSE), then switches to the IB Diploma. *2023 IB average: 37 points. Pass rate: 99%. IGCSE: 66% A\/A.**

Patana defines the eastern expat school run. Class sizes sit between 22 and 26. Co-curricular depth is exceptional: full sport, three orchestras, a 940-seat theatre, and the BISAC and SEASAC circuits.

Founded 1957. Pupils 2,300. Fees THB 495,000 to 975,000 (USD 14,100 to 27,800). Accreditation CIS re-accredited 2022, FOBISIA founding member. Thai nationals face a separate admissions track with a January 15 deadline.

3. International School Bangkok

ISB is the city's American school and the oldest international school in the region (1951). The campus sits inside Nichada Thani, a 395-acre gated community in Nonthaburi where most ISB families also live. The school runs an American programme with AP and the IB Diploma in the upper grades; the 2023 IB average was 34 points.

ISB is not for everyone. The location is forty-five to sixty minutes from central Bangkok in traffic, and the school runs within the rhythm of the compound rather than the city. Children in Nichada walk and cycle to school in a way uncommon elsewhere in Bangkok. A commute from outside the compound becomes punitive within a term.

Founded 1951. Pupils around 1,800. Fees THB 640,000 to 1,162,000 (USD 18,200 to 33,200). Accreditation WASC and CIS. Separate application tracks for Thai, dual-national, and expatriate applicants.

4. Shrewsbury International School Bangkok

Shrewsbury is the senior school of the Bangkok British market and the school that established the full English independent model in the city. The Riverside campus on the Chao Phraya in Khlong San takes Years 1 to 13; the City campus on Rama III takes early years and junior.

The 2025 senior school results: *74% A\/A at IGCSE, 89.4% A/B at AS, 65.2% A\/A at A-Level*. University destinations skew Russell Group with a strong UK-US-Hong Kong split. Class sizes are tighter than at the larger Sukhumvit majors, and sport, music, and drama run as timetabled core rather than optional enrichment.

Founded 2003. Pupils roughly 2,000 across both campuses. Fees THB 669,600 to 1,208,400 (USD 19,100 to 34,500). Accreditation CIS at both campuses, FOBISIA, BISAC.

5. Harrow International School Bangkok

Harrow was the first Harrow campus outside the UK (1998) and the oldest of the British-brand transplants in Thailand. The 2021 move to a 90-acre Sai Noi site pushed the school further north than the Sukhumvit cluster, in exchange for genuine boarding facilities, a full lake, and the only Year-7-up boarding programme realistically available to non-Thai families in Bangkok.

Published 2020 headlines: *68% A\/A at A-Level, 67% A\/A at IGCSE*. The pastoral system follows the Harrow house model. Music, debating, and competitive sport are strong; the school feels older and more institutional than newer entrants.

Founded 1998. Pupils around 1,900. Fees THB 136,800 to 1,037,100 (the low end is very early years; the senior fee sits near THB 990,000, USD 28,200). Accreditation BSO-inspected March 2023, FOBISIA since 2001.

6. King's College International School Bangkok

King's Bangkok is the strongest of the newer UK-brand entrants. The Ratchada campus opened in 2018 as the international branch of King's College School Wimbledon (England, 1829), one of the consistently top-performing UK independents. The 2024 BSO inspection awarded an Outstanding rating and Education Development Trust Gold.

Published academic results are exceptional against cohort size: *90% A\/A at A-Level and 98% A\/A at IGCSE in 2023*. These are the highest A-Level grade percentages of any Bangkok school. The cohort remains small enough that the headlines benefit from selectivity; the operating model carries the Wimbledon pedagogy through.

Founded 2018. Pupils still scaling. Fees THB 616,000 to 1,063,000 (USD 17,600 to 30,400). Accreditation BSO Outstanding 2024, FOBISIA 2021, UK DfE-registered British School Overseas.

7. Bangkok Prep

Bangkok Prep is the strongest non-UK-brand A-Level school in the city and the best-value option for families who want the full British exam pathway without the Shrewsbury or Harrow fee tier. The Sukhumvit 77 campus on On Nut sits inside the central expat catchment, much closer in than Patana or Harrow.

The 2025 results: *IGCSE 92% A\-C with 58% A\/A; A-Level 72% A\-B with 52% A\/A. Those numbers put Bangkok Prep in front of every Bangkok school except Shrewsbury, Harrow, and King's on A-Level outcomes, at noticeably lower fees. The school was triple-accredited by CIS and NEASC in 2011*.

Founded 2003. Pupils 1,700. Fees THB 295,000 to 821,100 (USD 8,400 to 23,500). Accreditation CIS and NEASC, FOBISIA, BISAC, TISAC, Duke of Edinburgh.

8. Brighton College Bangkok

The original Brighton campus on Krungthep Kreetha is a 20-acre eastern Bangkok site that opened in 2016 as the first Brighton outside the UK. The published headlines are strong against cohort size: *80% A\-A at IGCSE (50% at A\/A) and 80% A-B at A-Level*. A second Brighton campus opened in Vibhavadi (north Bangkok, near Don Mueang) in September 2025; the original eastern campus remains the senior school.

Krungthep Kreetha is about thirty minutes from downtown and fifteen minutes from Suvarnabhumi, which makes it the natural choice for families based on the eastern corridor or who fly often. The new Vibhavadi campus opens an alternative for north-Bangkok families who do not want the Sai Noi commute to Harrow.

Founded 2016 (Krungthep Kreetha). Fees THB 590,300 to 1,021,800 (USD 16,900 to 29,200). Accreditation BSO.

9. Concordian International School

Concordian is the strongest of the full-continuum IB schools outside NIST, Patana, and ISB. Founded in 2001 as a trilingual school in Samut Prakan, it runs the IB Primary Years, Middle Years, and Diploma Programmes with English, Mandarin, and Thai integrated through the curriculum rather than taught as separate languages.

The 2024 IB Diploma cohort averaged 36 points, upper-quartile globally and within a point of ISB. The school is CIS and NEASC accredited and runs a smaller, more intimate operation than the central anchors at around 900 pupils. The Samut Prakan location is a real consideration: reasonable from the eastern corridor or Bangna, long from central Sukhumvit.

Founded 2001. Pupils around 900. Fees THB 626,400 to 963,400 (USD 17,800 to 27,500). Accreditation CIS, NEASC, IB authorised at all three programmes.

10. Bromsgrove International School Thailand

Bromsgrove is the smaller, quieter UK-brand option. The Don Mueang campus runs a deliberately compact through-school of around 500 pupils, with 100% pass rates at both A-Level and IGCSE in 2025.

The numbers matter less than the operating philosophy. Bromsgrove keeps year groups small, teaches with the individual-attention culture of a UK prep school rather than the throughput of a 2,000-pupil flagship, and holds CIS accreditation plus Education Development Trust Gold. What the school loses in breadth it gains in everyone-knows-everyone culture.

Founded 2002. Pupils around 500. Fees THB 361,200 to 743,700 (USD 10,300 to 21,200). Accreditation CIS, EDT Gold.

At a glance

School	Area	Curriculum	Ages	Fees range (THB)	Standout
NIST	Sukhumvit 15	IB	3–18	628,000–1,094,500	IB 37 / 100% pass / 28% at 40+
Bangkok Patana	Sukhumvit 105	British, IB DP	2–18	495,000–975,000	IB 37 / 99% pass; 940-seat theatre
ISB	Nichada Thani	American, AP, IB	3–18	640,000–1,162,000	Oldest in Thailand (1951); compound life
Shrewsbury Riverside	Khlong San	British, A-Level	2–18	669,600–1,208,400	65% A\*/A at A-Level (2025)
Harrow Bangkok	Sai Noi	British, A-Level	2–18	137,000–1,037,000	Boarding; 90-acre campus
King's College Bangkok	Ratchada	British, A-Level	2–18	616,000–1,063,000	BSO Outstanding; 90% A\*/A A-Level
Bangkok Prep	Sukhumvit 77	British, A-Level	2–18	295,000–821,100	52% A\*/A A-Level at mid-tier fees
Brighton College	Krungthep Kreetha	British, A-Level	2–18	590,300–1,021,800	80% A-B A-Level; eastern corridor
Concordian	Samut Prakan	IB (PYP/MYP/DP)	2–18	626,400–963,400	Trilingual; IB 36 average
Bromsgrove (BIST)	Don Mueang	British, A-Level	2–18	361,200–743,700	100% A-Level pass; small cohort

Fees in Thai baht for the 2025-2026 school year. Indicative USD ranges in the school sections use a THB 35 to USD 1 conversion. Verify current figures with each school.

How this list was built

The starting universe was every Bangkok school that publishes externally inspected results, holds at least one of CIS, NEASC, WASC, COBIS, or BSO accreditation, and runs an English-language international curriculum (American, British, or IB) across primary and secondary. The ranking weighted four signals:

Operating history. Schools with two decades or more of cohort data sit ahead of newer entrants on the same headline numbers, because a single strong cohort is easier to produce than ten consecutive ones.
Externally inspected outcomes. Published IB averages and A-Level grade distributions from the most recent two or three years, against world averages. Cohort size matters: 30% A\/A across 200 students is a different signal from 90% A\/A across 12.
Curriculum integrity end-to-end. Schools that deliver the same model from early years to graduation rank ahead of schools that switch models mid-way for non-pedagogical reasons.
Scale and pastoral fit. A 2,300-pupil through-school and a 500-pupil prep school answer different family questions. Both can be excellent. Neither suits every family.

Schools excluded that came close: Wellington College Bangkok, Regent's International School, the two St Andrews campuses, and DBS Denla British School. None displaced the ten above on the combined criteria for 2025-2026.

How to use this list

A top-ten list is a starting point, not a verdict. The decision narrows on three axes.

Curriculum at senior. A-Level at Shrewsbury, Harrow, King's, Brighton, Bangkok Prep, and Bromsgrove. IB Diploma at NIST, Patana (after IGCSE), Concordian, and as one option at ISB. IB is six subjects plus core (Extended Essay, Theory of Knowledge, CAS); A-Level is three to four subjects taken deeper. Neither is harder; they are different shapes and suit different students.

Location and traffic. Bangkok is a one-hour city. A school 12 km away can be 25 minutes or 80 minutes depending on the day. Patana works for the eastern Sukhumvit cluster; Shrewsbury Riverside works for Sathorn, Bang Rak, and Khlong San; Harrow and Bromsgrove are northern; King's and Brighton are central-eastern; ISB is its own world in Nichada.

Fee tier and what it buys. The gap between the THB 1 million top of the market and the THB 800,000 mid-tier is real but smaller than the equivalent spread in Hong Kong or Singapore. The mid-tier (Patana, Bangkok Prep, Concordian) is genuinely good. The premium tier (NIST, ISB, Shrewsbury, Harrow, King's) buys smaller classes, deeper co-curricular provision, and more consistent staffing, not a different curriculum.

FAQs

Which is the single best international school in Bangkok? There is no single answer. The three schools that appear at the top of every credible list are NIST, Bangkok Patana, and International School Bangkok. NIST has the strongest recent IB results and the easiest central access. Patana has the deepest operating history and the broadest co-curricular bench. ISB has the longest American heritage and the Nichada compound model.

How do Bangkok fees compare to Singapore or Hong Kong? At the top of the market, Bangkok runs roughly 30 to 40% below Singapore and Hong Kong premium schools on a like-for-like basis. The mid-tier gap is wider still.

Which schools have waiting lists? NIST, Patana, ISB, and Shrewsbury Riverside have historically operated waiting lists at most year groups, particularly Years 3 to 8 and Year 12. Applications typically open 12 to 18 months before the August start. King's, Brighton Vibhavadi, and the August 2026 openings carry founding-year availability.

Is A-Level or IB the better choice in Bangkok? Both pathways are well established and well recognised. A-Level depth suits students who already know their subject direction; IB breadth suits students who want to keep options open. The school matters more than the qualification: a 65% A\*/A A-Level cohort and a 37-point IB average both place graduates into the same Russell Group and Ivy-League shortlists.

What about schools opening in August 2026? Dulwich College Bangkok, St Paul's Girls' School (SPGS) Bangkok, and Wycombe Abbey Bangkok all open in August 2026. None is on this list because none has cohort data, an inspection report, or an operating track record yet. The 2027 and 2028 editions will likely include at least one of them.

Sources. School-published academic results 2023 to 2025 (NIST, Bangkok Patana, Shrewsbury, Harrow, King's, Bangkok Prep, Brighton College, Concordian, Bromsgrove, ISB). British Schools Overseas inspection reports (Harrow 2023, King's 2024, Brighton). CIS accreditation register. NEASC accreditation register. FOBISIA membership directory. Education Development Trust (EDT) school awards register. International Schools Guide profile data for fees, accreditations, founding years, and pupil numbers.