Best IB Schools in Bangkok

Bangkok runs the second-strongest IB market in Southeast Asia, behind Singapore and ahead of Kuala Lumpur, Ho Chi Minh City and Jakarta. Eleven schools deliver the Diploma Programme to published cohorts; six clear the global average by four points or more.

The geography concentrates on Sukhumvit and the eastern corridor: NIST on Sukhumvit 31, Patana on Sukhumvit 105 (Bang Na), KIS Bangkok in Huai Khwang. ISB is the outlier twenty kilometres north in Nichada Thani; Concordian sits south-east in Samut Prakan; KIS Reignwood Park is 35 kilometres north in Pathum Thani.

A British-curriculum school that switches to IB Diploma at 16 (Patana, both St Andrews campuses) is a different proposition from a school running the full IB continuum from PYP through DP (NIST, Concordian, KIS, ISB). Both produce strong Diploma graduates; the inside-school experience is structured differently.

The top tier

Two decades of cohorts, averages well above the world mean, the accreditation and co-curricular depth of an established senior school.

Bangkok Patana School

Sukhumvit 105 (Bang Na). Ages 2 to 18. CIS re-accredited 2022, FOBISIA founding member 1988. 2,300 pupils. Head: Chris Sammons. Founded 1957.

Patana is the oldest international school in Thailand and runs the deepest IB Diploma cohort in the country. The school teaches the English National Curriculum from Foundation Stage to IGCSE at Year 11, then switches the entire senior school to the IB Diploma. *The 2023 cohort: 37 points average, 99% pass rate, 66% A\/A at IGCSE the year before.** A 37-point average puts Patana inside the top decile of IB World Schools globally.

The Sukhumvit 105 campus defines the eastern expat school run. Class sizes settle at 22 to 26. Co-curricular depth is unusual for the region: full sport, three orchestras, a 940-seat theatre. Students arrive at the Diploma with two years of IGCSE preparation behind them.

NIST International School Bangkok

Sukhumvit 31. Ages 3 to 18. CIS and NEASC dual-accredited, IB World School running all four programmes (PYP, MYP, DP, CP). 1,800 pupils. Head: James Dalziel. Founded 1992.

NIST is the only school in Thailand built around the IB from the ground up, with no British or American sub-structure underneath. The Diploma cohort is the largest in the country: 110 candidates in 2025, 100% pass rate against an 81% global average, 28% at 40+ against a 9% global rate, two students at the maximum 45.

Sukhumvit 31 is central to most expat residential clusters. Cohort diversity is the second selling point: more than seventy nationalities, no dominant national group above 15%. Families choosing NIST are choosing IB explicitly, not as the senior phase of a British or American school.

International School Bangkok

Nichada Thani, Nonthaburi. Ages 3 to 18. WASC and CIS accredited. ~1,800 pupils. Head: Debi Caskey. Founded 1951.

ISB is the second-oldest international school in Thailand and runs a hybrid model rare in Bangkok: an American programme from PreK through Grade 12, with the IB Diploma offered alongside AP in the upper school. The 2023 IB DP average: 34 points.

Nichada Thani is a self-contained gated expat community twenty kilometres north of central Bangkok; ISB sits inside the compound. Most ISB families live in or near Nichada; for families based further south the school run is the real cost. Fees top out at THB 1.16 million (~USD 32k), the highest in the Bangkok IB market.

Strong mid-tier

Smaller cohorts, similar accreditation, IB results three to five points above the world average, fees USD 2k to 6k a year below the top tier.

KIS International School Reignwood Park

Pathum Thani, north of Bangkok. Ages 3 to 18. CIS-accredited. 800 pupils. Head: Khanum Thampi. Reignwood Park campus opened 2019.

KIS Reignwood Park is the sister campus of KIS Bangkok, on a 100-rai (40-acre) site at the northern edge of Greater Bangkok. The 2024 Diploma cohort: 35-point average and more than 700 university offers. Campus scale is the differentiator: outdoor learning environments, a working farm, dedicated specialist facilities for music, drama and sport. Class sizes settle at 12 to 16. The commute is the cost.

Concordian International School

Bang Na-Trad, Samut Prakan. Ages 2 to 18. IB PYP, MYP and DP authorised; CIS and NEASC accredited. ~900 pupils. Head: Laurent Goetschmann. Founded 2001.

Concordian is the strongest trilingual full-continuum IB school in Bangkok, teaching in English, Mandarin and Thai from PYP onward. The 2024 Diploma cohort averaged 36 points, four points above the global mean. For families committed to a multilingual IB pathway from age two, the alternatives in Bangkok are thin.

KIS International School Bangkok

Huai Khwang. Ages 3 to 19. CIS re-accredited 2023. ~700 pupils. Head: Dr Carolyn Mason Parker. Founded 1998.

KIS Bangkok runs the full IB continuum (PYP, MYP, DP) on a compact urban campus near Cultural Centre MRT. The 2022 Diploma cohort: 33-point average, 90% pass rate. Smaller and more central than its Reignwood Park sister; less outdoor space, smaller sports facilities, single primary class per year group. The compensation is location: the most centrally located full-continuum IB school in the city.

Ruamrudee International School

Min Buri, eastern Bangkok. Ages 2 to 18. IB Diploma alongside AP. ~1,100 pupils. Head: Dr James O'Malley. Founded 1957.

Ruamrudee is one of the two oldest international schools in Thailand (founded the same year as Patana). It runs an American programme through to a dual IB/AP exit: 97% IB pass rate, 34-point average, 45 AP exams administered in the most recent published cycle. Min Buri puts the school 25 kilometres east of central Bangkok; the return is space: large playing fields, a 25-metre pool, dedicated music and drama facilities on a site bigger than most central-Bangkok schools combined.

St Andrews International School Bangkok (Sukhumvit 71)

Phra Khanong, Sukhumvit 71. Ages 2 to 18. Nord Anglia-operated. ~2,300 pupils. Head: Paul Schofield.

St Andrews Sukhumvit 71 runs an English National Curriculum primary into IB Diploma at sixth form, the same hybrid shape as Patana but at lower fees. *The 2025 cohort: 34.4 average, 96% pass rate, 90% A\-C at IGCSE the year before.**

Two notes on the St Andrews name in Bangkok. Sukhumvit 71 is the Nord Anglia campus with the published IB record above. Sukhumvit 107 (Bearing) is independently operated under shared branding; it is also an IB World School but does not publish DP averages in the same form. Curriculum philosophy is similar; governance is not.

Best for full IB continuum (PYP, MYP and DP)

For families committed to an IB philosophy from age three, the shortlist tightens to schools running all three programmes under one roof.

• NIST is the only school in Thailand purpose-built around the IB from foundation, with no other curriculum underneath. The MYP-to-DP transition is the smoothest.
• Concordian runs the trilingual PYP-MYP-DP pathway with the strongest published DP average (36) among full-continuum schools.
• KIS (Bangkok and Reignwood Park) run the same continuum across two campuses; Reignwood Park has the stronger recent DP result (35), Bangkok the more central location.
• Pan-Asia International School runs MYP and DP without a PYP layer; smaller (~400 pupils), DP results published since 2010 without specific cohort averages.
• Roong Aroon International School is the newest entrant (founded 2019, MYP/DP/CP authorised). The 2025 cohort posted 34 average and 94% pass rate on a very small intake.

Full continuum is not automatically better than a hybrid pathway. Patana, ISB and the St Andrews campuses produce strong DP results without PYP or MYP underneath. The argument for the continuum is consistency of pedagogy. A weak MYP can leave students less prepared for the Diploma than two years of IGCSE would.

At a glance

Fees converted from THB to USD at indicative 2026 rates (THB 36.4 per USD). The low end is typically nursery or early years; the high end is sixth form. Verify current figures with each school.

The four IB programmes

The International Baccalaureate runs as four programmes. Bangkok schools offer the first three commonly and the fourth rarely.

PYP (ages 3 to 12) is inquiry-led and transdisciplinary. No external exams; the programme culminates in the PYP Exhibition at Year 6. Quality depends heavily on staff capability.

MYP (ages 11 to 16) uses eight subject groups, a Personal Project, and largely criterion-referenced school-based assessment. No external standardised exam at 16. Execution variance is greatest here. NIST, Concordian and KIS execute MYP at a level that flows naturally into a strong DP cohort.

DP (ages 16 to 19) is the qualification universities recognise. Six subjects (three Higher Level, three Standard Level) plus Theory of Knowledge, Extended Essay, and CAS. Graded out of 45 points. The 2024 worldwide average was 30.32. Bangkok's strongest schools sit five to seven points above that.

Career-related Programme (CP) is uncommon: NIST, Pan-Asia and Roong Aroon offer it; most others do not. Only the Diploma carries the international university currency. Before short-listing, confirm which programmes a school is currently authorised for; the IB public directory is the definitive source.

How to choose between them

The decision usually narrows on four axes.

Full continuum vs hybrid pathway. PYP-MYP-DP from age three gives consistency of pedagogy. ENC or American primary then IB Diploma at sixth form gives external exam preparation through IGCSE before the Diploma workload begins. Neither produces stronger DP results in aggregate. Patana's 37-point average shows what an IGCSE-then-DP pathway delivers; NIST's 28% at 40+ shows what continuum DP delivers.

Cohort size at DP. 110 candidates (NIST) offers a broader subject roster, more competition, deeper teacher specialisation. 20 (Concordian, KIS Bangkok) offers smaller classes, more individual attention, a narrower subject menu. Ask each school for the actual DP subject list, current cohort, and HL combinations on offer.

Location and traffic. Bangkok is a one-hour city. NIST, KIS Bangkok and Wells sit central; Patana and St Andrews 71 anchor the eastern run; ISB, KIS Reignwood Park and Concordian sit outside the core ring. Run the actual commute at school-run hour before committing.

Fee tier. The gap between the top of the market (ISB, NIST, KIS RP at THB 950k+) and the strong mid-tier (St Andrews 71, Wells at THB 550k to 850k) is real but narrower than in Hong Kong or Singapore. The premium tier buys larger campuses, deeper co-curricular provision, stronger university counselling and longer-tenured staff. It does not buy a different curriculum.

Related reading

• Best international schools in Bangkok (the city pillar across all curricula).
• Best British schools in Bangkok.
• What is the IB Diploma?
• IB HL vs SL
• IB vs A-Levels
• British vs IB vs American curriculum
• What is CIS accreditation?

FAQs

Which is the best IB school in Bangkok?

For published Diploma average, Patana leads with 37 points (2023, 99% pass). For the strongest tail of top scorers, NIST with 28% of the 2025 cohort at 40+ against a global rate of 9%, 100% pass. Patana switches to IB Diploma at sixth form after an ENC primary; NIST runs the full IB continuum from age three. Both sit inside the top decile of IB World Schools globally.

What is a good IB score in Bangkok?

The 2024 global average is 30.32. Bangkok's leading schools clear that comfortably: Patana 37, Concordian 36, KIS Reignwood Park 35, NIST and ISB and St Andrews 71 in the 34 to 34.4 range. A 30+ score from any accredited Bangkok school is a defensible result; 33+ is competitive for selective universities; 38+ is regionally exceptional.

Does my child need to do IB PYP and MYP to do well at IB Diploma?

No. The strongest published DP average in Bangkok (Patana, 37) comes from a school where students do IGCSE first, not MYP. The case for full continuum is consistency of pedagogy, not stronger results.

Are there affordable IB schools in Bangkok?

Below the USD 20k mark, Wells (Sukhumvit 22, DP), Pan-Asia (MYP and DP), and Roong Aroon (secondary IB, opened 2019) all carry IB authorisation at lower fees than the top tier. The trades are real: smaller cohorts, less published exam data, narrower HL subject rosters.

How do I verify a Bangkok school's IB authorisation?

The IB Organisation publishes a directory of authorised World Schools at ibo.org/programmes/find-an-ib-school. School marketing sometimes describes historical or in-progress authorisations as current; the IB directory is definitive.

Sources: IB Organisation public school directory (programme authorisations); published school IB Diploma results 2022–2025 (school websites); CIS, NEASC, WASC member registers; Thai Ministry of Education international school list. Fee data from official school fee schedules; conversions at indicative 2026 THB/USD rates (THB 36.4 per USD). The 2024 worldwide IB Diploma average of 30.32 from IB Organisation Statistical Bulletin May 2024.