The Îles de Los ([il də lo]) are an island group lying off Conakry, Guinea, on the west coast of Africa.

The ring shape of the Îles de Los belie their origins as a volcanic structure, an igneous intrusion amid the sediments of the West African continental shelf, which dates to the Cretaceous Period during the opening of the South Atlantic Ocean.

[3] The archipelago is composed of the uncommon rock syenite, also found in similar volcanic structures such as the Monteregian Hills in Quebec or the Ilimaussaq intrusive complex in Greenland.

[5] In 1755, Miles Barber of the African Company of Liverpool established a trading post (then known as a factory) there employing workers skilled in ship repair as well as pilots for the local rivers.

Charles MacCarthy, the Governor of Sierra Leone, signed a treaty with Mangé Demba on 6 July 1818, whereby the islands were ceded to the British Empire for the payment of an annual rent.