Macquarie Island (or Macca) lies in the southwest corner of the Pacific Ocean, about half-way between New Zealand and Antarctica, at 54°30S, 158°57E. Politically, it is part of Tasmania, Australia since 1900 and became a Tasmanian State Reserve in 1978. In 1997 it became a World Heritage Site. It was a part of Esperance Municipality until 1993, when the municipality was merged with other municipalities to Huon Valley. The island is home to the entire Royal Penguin population on earth during their annual nesting season. Ecologically, it is part of the Antipodes Subantarctic Islands tundra ecoregion.

Since 1948 the Australian Antarctic Division (AAD) has maintained a permanent base, the Macquarie Island Station, on the isthmus at the northern end of the island at the foot of Wireless Hill. The population of the base, the island's only human inhabitants, usually varies from 20 to 40 people over the year.

The Australian/Briton Frederick Hasselborough discovered the uninhabited island accidentally on 11 July 1810 when looking for new sealing grounds. He claimed Macquarie Island for Britain and annexed it to the colony of New South Wales in 1810. The island took its name after Colonel Lachlan Macquarie, Governor of New South Wales from 1810 to 1821. Hasselborough reported a wreck "of ancient design", which has given rise to speculation that the island may have been visited before by Polynesians or others.