OSC earns global recognition through tri-agency accreditation

The Overseas School of Colombo (OSC) has once again demonstrated why it is Sri Lanka’s leading international school, following a successful tri-agency accreditation involving the International Baccalaureate (IB), Council of International Schools (CIS) and Middle States Association of Colleges and Schools (MSA).

This joint visit resulted in a powerful endorsement from all three global accrediting bodies – a testament to OSC’s consistent commitment to excellence, innovation and continuous improvement. Uniquely, OSC remains the only dually accredited (CIS/MSA) international school in Sri Lanka.

While the CIS and MSA are independent organisations, their evaluation was conducted as a unified team. The CIS/MSA findings reflect this seamless partnership.

OSC’s accreditation journey dates back to 1990 for the CIS/MSA and to 1983 for the IB Diploma Programme. The school later added the IB Middle Years Programme in 1999 and Primary Years Programme in 2002, affirming its commitment to a rigorous, inquiry-driven curriculum.

The IB is a Geneva-based foundation promoting global-mindedness and critical thinking through its internationally recognised programmes. The CIS, headquartered in the Netherlands, accredits schools focused on intercultural learning, well-being and ethical leadership. The MSA, one of the oldest US accreditation agencies, evaluates student outcomes and institutional integrity.

Over four days, 10 global evaluators engaged deeply with the OSC community. They encountered a school not just meeting benchmarks but redefining them.

“OSC is an international school exemplar,” stated the CIS/MSA team. 

“It is more than an international IB school – it is a community-driven school with a strong sense of shared purpose.”

The IB praised OSC’s Teacher Growth and Improvement Framework, calling it “the best the IB has ever seen” – describing it as “research-backed and comprehensive”.

The evaluators consistently highlighted OSC’s caring, inclusive culture and its focus on student agency and well-being. 

“Learning at OSC is dynamic,” noted the IB team, citing strong service-learning opportunities. 

“The students explain their learning clearly,” added the CIS/MSA team – a reflection of OSC’s student-centred approach.

Special recognition was given to OSC Internal Coordinator Accreditation Coert Van Zijl for producing a self-study described as a “model example” for other schools.

Head of School Dr. Michelle Kleiss attributed this success to the strength of the school’s academic leadership, professional learning culture, seamless operations and the active participation of students, faculty and families.