Kinabalu International School has been in existence for nearly 40 years. It was originally established to provide a British type education for children of expatriates living and working in Sabah. Until this time, expatriate children had attended the local government schools where the medium of instruction was English. However, when the Malaysian Government decided that the medium of instruction in local schools was to be Bahasa Malaysia, it was no longer feasible for expatriate children to attend these schools. Hence, Kinabalu International School was born. Initially, premises were rented from the St John’s Ambulance Association, and the teachers were parents of the pupils attending the school. Gradually, qualified teachers were recruited, and the school moved to rented premises in the former St. Agnes Hostel in Likas. KIS remained there for thirteen years until the lease on the buildings expired. The school then moved to a renovated house in Sunny Garden. It was at this time that the parent body took the decision to build its own school buildings at Bukit Padang.

After a tremendous amount of work and fund-raising by the parent body, the school buildings were opened in 1995. KIS can proudly claim to be the only international school in Malaysia that owns its school freehold without any loans at all. This is testament to the commitment and support the school has traditionally enjoyed from the parent population throughout the school’s history. Over the years the school has received recognition of its commitment to high standards from various educational organisations and in 1988, KIS became a founder member of the Federation of British International Schools in South and South East Asia (FOBISSEA) and has been able to maintain its membership through its commitment to educational excellence. 

In the year 2000, Year 10 & 11 classes were introduced to enable pupils to study for the International General Certificate of Secondary Education (IGCSE). This necessitated the building of a dedicated secondary department block of classrooms, complete with science laboratories, in 2001. At the same time the school updated teaching resources throughout the whole secondary department – a process that has been continued on an annual basis ever since.    The year 2001 also witnessed the creation of an ICT Laboratory to ensure that students have every opportunity to develop high levels of computer literacy. At the 2004 Annual General Meeting, the Parent Body passed a motion to build the proposed double storey multi-purpose hall which was completed shortly thereafter. As the school continued to expand another major building project was undertaken in 2009 with the completion of a new four storey building housing classrooms, a new school library and a staffroom. 2010 saw the opening of the new KIS playgroup, 'First Steps @ KIS' in one of the new classrooms in this building.

The 2009-2010 academic year also saw the school being granted membership of the globally renown ‘Council of International Schools’ as well as embarking on an 18 month self-study process as part of its quest to achieve full accreditation status with this much-respected organisation. Kinabalu International School is still owned and managed by the parent body and as such there remains an on-going commitment to be innovative and sensitive to the changing needs of the whole school community.