The Montessori School in Kingsley was founded by Mrs W. M. Duyker-de-Vries in 1962 and is the oldest Montessori School in Australia. It is the first Montessori school in Western Australia to include a secondary school for students from 12 to 18 years old and the first Montessori School in the world to offer the International Baccalaureate (IB) Diploma course, an internationally recognised university entrance qualification.
Initially the school catered for pre-primary children only, with a primary section being added in 1965 and secondary in 1972. The Montessori School became an International Baccalaureate (IB) school in 1993.