The British Indian Ocean Territory (BIOT) is a British overseas territory of the United Kingdom situated in the Indian Ocean halfway between Africa and Indonesia. The territory comprises the seven atolls of the Chagos Archipelago with over 1,000 individual islands – many very small – amounting to a total land area of 60 square kilometres (23 sq mi). The largest and most southerly island is Diego Garcia, 27 km2 (10 sq mi), the site of a joint military facility of the United Kingdom and the United States.

The only inhabitants are US and British military personnel, who collectively number around 3,000. The forced removal of Chagossians from the Chagos Archipelago occurred between 1968 and 1973. The Chagossians, then numbering about 2,000 people, were expelled by the UK government to Mauritius and Seychelles to allow the United States to build a joint UK–US military base there. Today, the exiled Chagossians are still trying to return, pointing out that the forced expulsion and dispossession was illegal, but the UK government has repeatedly denied them the right of return.