What strait separates Australia from Papua New Guinea?

The strait separating Australia from Papua New Guinea is the Torres Strait.

It lies between Cape York Peninsula, Australia’s northernmost mainland region, and the southern coast of New Guinea. The passage is about 150 kilometres wide at its narrowest extent and contains hundreds of islands, including the culturally significant Torres Strait Islands.

The strait is named after Luís Vaz de Torres, a Portuguese navigator sailing under the Spanish crown. In 1606, Torres travelled along the southern coast of New Guinea and passed through the waterway, though European maps did not immediately make the passage widely known. Scottish geographer Alexander Dalrymple later helped bring Torres’s account to wider attention.

The Torres Strait is more than a geographic divide: it is also a maritime boundary between Australia and Papua New Guinea. The 1978 Torres Strait Treaty, which took effect in 1985, established borders while protecting traditional movement and fishing practices for Indigenous communities. It is sometimes confused with the Arafura Sea, which lies west of the strait.