Horn Island, or Ngurupai/Narupai in the local language, is an island of the Torres Strait Islands archipelago located in the Torres Strait, in Queensland in Northern Australia between the Australian mainland and Papua New Guinea. It is within the locality of Horn within the Shire of Torres; the boundaries of the locality include the island itself and surrounding waters of the Torres Strait. The town of Wasaga is on the north-western coast of the island. In the 2021 census, the locality of Horn had a population of 533 people.

The Torres Strait Islands are an archipelago of at least 274 small islands in the Torres Strait, a waterway separating far northern continental Australia's Cape York Peninsula and the island of New Guinea. They span an area of 48,000 km2 (19,000 sq mi), but their total land area is 566 km2 (219 sq mi).