Hoste is one of the southernmost islands in Chile, lying south, across the Beagle Channel, from Isla Grande de Tierra del Fuego and west of Navarino Island, from which it is separated by the Murray Channel. With an area of 4117 km², Hoste is the second largest island of the Tierra del Fuego archipelago, after Isla Grande de Tierra del Fuego. The island is located in the Commune of Cabo de Hornos, which belongs to the Antártica Chilena Province of the Magallanes y Antártica Chilena Region. The western area of the island forms part of the Alberto de Agostini National Park. The most southern point of the island is the False Cape Horn, on the Hardy Peninsula. The highest point of the island is at 1402 meters.
The island was explored by a French scientific expedition towards the end of the 19th century. Already before, there have been unsuccessful cattle farming attempts of the Chilean government, after which the island had been abandoned. Well into the 20th century, a few Yamana families lived on the island. Those indigenous people vanished after contact with adventurers and fishermen. Since then, the island has been virtually uninhabited. The 1992 census reported a population of six, among three residential buildings in the Hoste census district (, whereby some or all of this population could be located on one or more smaller islands close by, that also belong to the district). In 1978, the island served as a station for Chilean warships during Operation Soberania.
Hoste Island has the southernmost trees on earth (Nothofagus antarctica).