Traill International School

Traill International School was founded in 1966 by Anthony Traill, a former British Olympic athletics coach who had coached Thailand's team, and his wife. It was first known as The Preparatory School and describes itself as the first British secondary school in Thailand. The Traill family are still involved as governors and directors. The campus is on Ramkhamhaeng 16 in Hua Mak, Bang Kapi, close to the Rama 9 and Ramkhamhaeng junction, with expressway links to Sukhumvit, Asok and Silom.

The school teaches the British curriculum from Pre-KG (age 2) through Kindergarten and Primary to Year 6. Secondary pupils follow a Middle Years programme in Key Stage 3, then Cambridge IGCSEs in Years 10 and 11. The Sixth Form offers AS and A Levels, with a diploma course as an alternative pathway. Classes are small, a team of specialist teachers supports pupils who arrive with limited English, and Thai language and culture are taught. The school holds Education Development Trust's ISQM accreditation, and its 2024 report rated pupils' personal development as outstanding.

The campus has a swimming pool, an indoor sports hall, playing fields, a library, science and specialist rooms, and a boarding house for students from Year 9. Tuition for 2026–27 is THB 370,800 a year in Kindergarten, THB 404,100 to 459,600 in primary, THB 501,900 in Years 7 and 8, THB 530,700 in Year 9, THB 572,700 for IGCSE and THB 577,650 in the Sixth Form. A meal plan (THB 28,500 a year) and resource and facilities fees are extra. Boarding costs THB 120,000 a term. There is a one-off THB 130,000 registration fee and a refundable THB 35,000 deposit.