Kutai is a Malayic language spoken by 300,000 to 500,000 people. It is the native language of the Kutai people, the indigenous ethnic group which lives along the Mahakam River in Borneo, especially in East Kalimantan, Indonesia. They are the principal population in the regencies of West Kutai, Kutai Kartanegara, and East Kutai within East Kalimantan province.
Kutai is part of the local Bornean Malayic languages and is closely related to but distinct from the Banjar language in South Kalimantan, Berau, also spoken in North Kalimantan and to some extent Brunei-Kedayan Malay as well. Kutai forms a dialect continuum between the two varieties and all three share similar phonology and vocabulary with each other.