Siberut is the largest and northernmost of the Mentawai Islands, located 150 kilometres west of Sumatra in the Indian Ocean. It covers an area of 3,838.25 km2 including smaller offshore islands, and had a population of 35,091 at the 2010 Census and 40,220 at the 2020 Census. A part of Indonesia, the island is the most important home for the Mentawai people. The western half of the island was set aside as the Siberut National Park in 1993. Much of the island is covered with rainforest, but is subject to commercial logging.