ISS International School Singapore

ISS International School was founded in 1981 by Singaporean politician Chan Chee Seng and was originally known as the International School of Singapore. Since 2020 all year groups have been on one campus at 21 Preston Road, a wooded hilltop off Alexandra Road. The site's colonial-era buildings once housed Alexandra Grammar School for British military families.

ISS is an IB World School offering the Primary Years, Middle Years and Diploma Programmes from Kindergarten to Grade 12. It also offers its own ISS High School Diploma as an alternative senior pathway. Class sizes are kept small, and the school provides English as an Additional Language and learning-support programmes.

The school is accredited by CIS and WASC and holds EduTrust certification. In 2026/27, total course fees run from about S$27,700 a year in the primary years to about S$57,000 in Grade 12. ISS is a day school.