West Kotawaringin Regency

West Kotawaringin Regency (Kabupaten Kotawaringin Barat) is one of the thirteen regencies which comprise the Central Kalimantan Province on the island of Kalimantan (Borneo), Indonesia. It originally comprised the whole western part of the province, having been split from a single Kotawaringin Regency on 26 June 1959 into separate regencies for West and East Kotawaringin, but on 10 April 2002 the most westerly districts of West Kotawaringin were split off to form the new Lamandau Regency and Sukamara Regency. The residual West Kotawaringin Regency has a land area of about 10,759 km2, and its population was 235,803 at the 2010 Census and 270,388 at the 2020 Census; the official estimate as at mid 2023 was 279,740 (comprising 144,765 males and 134,975 females). The town of Pangkalan Bun in Arut Selatan District is the capital of West Kotawaringin Regency.

Administrative districts
West Kotawaringin Regency consists of six districts (kecamatan), tabulated below with their areas and population totals from the 2010 Census and the 2020 Census, together with the official estimates as at mid 2023. The table also includes the locations of the district administrative centres, the number of administrative villages in each district (a total of 81 rural desa and 13 urban kelurahan), and its post codes.

Notes: (a) including 2 kelurahan (Kotawaringin Hilir and Kotawaringin Hulu). (b) comprising 7 kelurahan (Baru, Madurejo, Mendawai, Mendawai Seberang, Raja, Raja Seberang and Sidorejo) and 13 desa. (c) including 3 kelurahan (Candi, Kumai Hilir and Kumai Hulu). (d) including 1 kelurahan (Pangkut).