The school was founded in 1925 by Anne Griffith-Jones. It is the oldest British international school in Southeast Asia.

At the time, many British expatriates living in Singapore sent their children away to boarding school in Britain at an early age. The school offered the alternative of providing British-style education in Singapore, so parents could postpone boarding school until an older age.

Tanglin Trust School provides British-based learning with an international perspective for students aged 3–18. 

The English National Curriculum provides the basis for the programmes of study. Infant School students are aged between 3 and 7 and the curriculum they follow is the Early Years Foundation Stage in Nursery and Reception followed by Key Stage 1 in Years 1 and 2. Students in the Junior School, aged between 7 and 11, follow Key Stage 2 in Years 3 to 6. Students in the Senior School, including those in the Sixth Form, are aged 11 to 18 years. They study Key Stages 3 in Years 7 to 9; Key Stage 4 in Years 10 and 11; and Key Stage 5 in Years 12 and 13. As students progress through Key Stage 3 to 5 of the English National Curriculum, they are presented with a widening choice of subjects to choose from for their General Certificate of Secondary Education (I/GCSE) and A Level or IB examinations. Tanglin’s Infant, Junior and Senior Schools are inspected every three years by Ofsted British Schools Overseas (BSO). The school has been repeatedly described by UK inspectors as Outstanding, the highest possible grade.

According to Wikipedia