Which Countries Share the Island of Borneo?

Political map of the island of Borneo.

Where is Borneo?

With an area of 287,000 square miles, Borneo is the third largest island in the world. The island is located in Southeast Asia in the Pacific Ocean. The island forms part of the Greater Sunda Islands. Borneo has a population of more than 19 million, the majority of which reside in coastal areas. The island experiences a hot and wet climate, making Borneo one of the most diverse regions in terms of its flora. The island, for example, hosts one of the world’s oldest rainforest (about 140 million years). The island is divided politically into three administrative countries: Indonesia, Malaysia, and Brunei.

Political Divisions of Borneo

Indonesian Borneo

Indonesia is one of the countries occupying the island of Borneo. With an area 210,097 square miles, Indonesia occupies about 73% of the island and is home to about 69% of the Borneans. Indonesia occupies the southern part of the island, referred to as the Kalimantan region, which means "burning weather island." Kalimantan has five administrative territories: West, Central, South, East, and North Kalimantan. These provinces are further divided into cities. Central Kalimantan is the largest state in the region, while West Kalimantan has the highest population. Previously, only four states existed until North Kalimantan split off from East Kalimantan. Kalimantan, or the Indonesian portion of Borneo, became independent in 1945. The economy of Kalimantan relies heavily on natural resources including forestry and oil extraction, as well as tourism and trade. The province of South Kalimantan, for example, is one of Indonesia’s largest producers of wood.

Malaysian Borneo

Malaysia occupies the second largest portion of Borneo, with an area of about 74,620 square miles, which is about 26% of the total island. Malaysian Borneo, known as East Malaysia, is divided into three states: Sabah, Sarawak, and Labuan. Sabah and Sarawak joined the Federation of Malaysia in 1957, previously existing as separate British colonies. Located off Sabah’s coast, Labuan existed as a part of Sabah until it became a federal territory in 1984. These states are part of the Malayan government, with a representation of 35% (47 seats) in the Malaysian Parliament. Debates about the autonomy of Sabah and Sarawak exist, as the two states still maintain their local government practices unlike other states in West Malaysia. East Malaysia has a population of about 5 million people, with the largest population in Sabah. Most of the East Malayan population is urbanized.


With an area of about 2,200 square miles, which is 1% of the island's total area, Brunei is the third country occupying Borneo. Unlike Indonesia and Malaysia, the entire country of Brunei is located on the Borneo island. The Brunei section of the island is located in the north, and is largely surrounded by the Malaysian Borneo state of Sarawak. Brunei has four administrative districts, namely Temburong, Brunei-Muara, Belait, and Tutong. Brunei attained independence from the United Kingdom in 1984, establishing itself as an absolute Islamic monarchy. Despite its small size, the region is endowed with numerous natural resources, particularly petroleum and natural gas. The extraction and export of petroleum products and natural gas have placed Brunei in the economic map as fifth richest nation according to Forbes magazine.


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