The Egan Islands, also known as Six Iles, is an uninhabited atoll administered by the United Kingdom. They are one of the few emerged coral atolls that make up the Chagos Archipelago in the British Indian Ocean Territory. Its total size is 29 km², including the lagoon and the fringing coral reef. The land area totals about 4 km². The nearest island is Danger Island on the Great Chagos Bank, less than 30 km due north. All islands are covered with coconut trees.
The largest island is "Île Sud-Est" (Eastern Egmont), with an area of 1.5 km². It was first settled in the last half of the 18th century, at the time when the other atolls of the Chagos were settled by the French. While "Île Lubine" is similar in size, the other islets are smaller. The Egmont Islands were no longer inhabited in the second half of the 20th century, at the time that the Chagossians or Ilois were evicted from the Chagos. In 1972–73 there was an underwater expedition to the Egmont Islands by the Joint Services (JSEI). Its aim was to study coral reef formation and growth, as well as the islands' flora and fauna. Following its success, a second expedition was undertaken to Danger Island the following year.