West Papua (Indonesian: Papua Barat), formerly Irian Jaya Barat (West Irian), is an Indonesian province located in Indonesia Papua. It covers most of the two western peninsulas of the island of New Guinea: the eastern half of the Bird's Head Peninsula (or Doberai Peninsula) and the whole of the Bomberai Peninsula, along with nearby smaller islands. The province is bordered to the north by the Pacific Ocean; to the west by Southwest Papua Province, the Halmahera Sea and the Ceram Sea; to the south by the Banda Sea; and to the east by the province of Central Papua and the Cenderawasih Bay. Manokwari is the province's capital and largest city. With an estimated population of 578,700 in mid-2024 (comprising 304,140 males and 274,560 females), West Papua is the second-least-populous province in Indonesia after South Papua, following the separation off in December 2022 of the western half of the Bird's Head Peninsula to create the new province of Southwest Papua, containing 52% of what had been West Papua's population. Its population density is similar to that of Russia.
After the Japanese surrender in 1945, the Dutch remained in New Guinea until 1962 when they transferred the control of the region to the Indonesian government as a part of the New York Agreement. West Papua was legally created as a province in 1999 (out of the original Papua Province), but it was not inaugurated until 2003. Consisting until 2022 of twelve regencies and one city, the province has a special autonomous status as granted by Indonesian legislation.