Kadazan-Dusun (also written as Kadazandusun) is the term assigned to the unification of the classification of two indigenous tribes in Sabah, Malaysia—the ethnic groups Kadazan and Dusun.

The designation is officially recognised as the result of a resolution of the 5th Kadazan Cultural Association (KCA) Delegates Conference held between November 4 and November 5, 1989 (KCA was later renamed to KDCA - Kadazan-Dusun Cultural Association [1]). During the conference, it was decided that this was the best alternative approach to resolve the "Kadazan" or "Dusun" identity crisis that had crippled and impeded the growth and development of the Kadazan-Dusun multi-ethnic community socio-culturally, economically and politically—ever since Kadazanism versus Dusunism sentiments were politicised in the early 1960s.

This was the basis that led to the United Sabah Dusun Association (USDA) and the Kadazandusun Cultural Association (KDCA) to resolve that the language to be taught in schools as the Pupils' Own Language (POL) shall be known as the Kadazandusun Language, based mainly on the Bundu-Liwan dialect and to be enriched by the other Kadazandusun dialects. In Universiti Malaysia Sabah (UMS), a Kadazandusun Chair has been established to undertake deeper research into and documentation of the Kadazandusun's heritage and culture. The university also offers the Kadazandusun language as an elective language subject, and it is quite popular among foreign students.