Great Barrier Island (often colloquially The Barrier) is the fourth-largest of New Zealand's main chain of islands. It is north-east of central Auckland in the outer Hauraki Gulf. It has an area of and its highest point, Mount Hobson, is . The local authority is the Auckland Council.
The island was initially exploited for its minerals and kauri trees and saw only some limited agriculture. It is now inhabited by 852 people, mostly living from farming and tourism. The majority of the diverse environments (around 60% of the total area) is administered as nature reserve by the Department of Conservation. In 2009 the island atmosphere was described as being "life in New Zealand many decades back", not without some positive emphasis.