What is the world's largest sand island?

K'gari is the world's largest sand island.

Located off Queensland's southeastern coast, K'gari is a long island built overwhelmingly from sand transported northward along Australia's coast by waves and longshore drift. It covers about 1,655 square kilometers and is separated from the mainland by the Great Sandy Strait. The island was officially renamed K'gari in 2023, restoring the Butchulla traditional name; Fraser Island remains its former European name.

K'gari is remarkable because its sandy ground supports much more than dunes. Rainforest, eucalyptus woodland, wallum heath, wetlands and peat swamps occur across the island. Naturally occurring fungi help plants obtain nutrients from the nutrient-poor sand, while perched lakes and freshwater creeks provide unusual habitats in the sand landscape.

The island became a UNESCO World Heritage Site in 1992. Its dunes have formed over hundreds of thousands of years, and the oldest dune sequence is dated to roughly 700,000 years. Nearby Moreton, North Stradbroke and Bribie islands are also sandy Queensland islands, but none is as large as K'gari.