Triam Udom Suksa School is a state school located in central Bangkok, Thailand. It admits upper-secondary students (mathayom 4–6, equivalent to grades 10–12) and has the largest yearly enrolment in the country. Founded in 1938 as a preparatory school for Chulalongkorn University, the school has long been regarded as one of the best secondary schools in Thailand, and attracts students from all over the country in its highly competitive entrance examinations. Triam Udom Suksa has among the highest university entry rates for Thai schools, and its students consistently score among the top in national standardised tests.