Kotawaringin, or Kota Waringin was a sultanate on the south coast of Borneo. It covered an area in what is now the western part of the Indonesian province of Central Kalimantan. It then had a brief existence as an autonomous "native state" in the United States of Indonesia between 1949 and 1950, before being formally created as a separate Kotawaringin Regency within what was then the Province of South Kalimantan (from which the western part (then consisting of three regencies - the kabupaten of Barito, Kapuas and Kotawaringin) was split off in 1957 to form the new Central Kalimantan Province). However, on 26 June 1959 Kotawaringin Regency was divided into a West Kotawaringin Regency and an East Kotawaringin Regency.

On 10 April 2002 additional regencies were created by splitting the two existing regencies - Sukamara and Lamandau from parts of West Kotawaringin Regency, and Seruyan and Katingan from parts of East Kotawaringin Regency.

In recent years, there has been some research into local attitudes, with a view to the putative re-establishment of Kotawaringin as a separate province, separate from the rest of Central Kalimantan, based upon the recognition of a shared identity of "Orang Kotawaringin".^[1] Such a province would cover an area of some 71,600 km² and would have a population as at 2023 of some 1.25 million people.^[2]

• East Kotawaringin Regency
• West Kotawaringin Regency

• Cribb, Robert (2000). Historical Atlas of Indonesia. Richmond, Surrey: Curzon Press. pp. 101, 160. ISBN 0-7007-0985-1.
• Kahin, George McTurnan (1952), Nationalism and Revolution in Indonesia, Ithaca, New York: Cornell University Press, p. 435