Lake Eyre, officially known as Kati Thanda–Lake Eyre, is an endorheic lake in east-central Far North South Australia, some 700 km north of Adelaide. The shallow lake is the depocentre of the vast endorheic Lake Eyre basin, and contains the lowest natural point in Australia at approximately 15 m below sea level, and on the rare occasions that it fills completely, is the largest lake in Australia covering an area up to 9,500 km². When the lake is full, it has the same salinity level as seawater, but becomes hypersaline as the lake dries up and the water evaporates.
The lake was named in honour of Edward John Eyre, the first European to see it in 1840. The lake's official name was changed in December 2012 to combine the name "Lake Eyre" with the Aboriginal name, Kati Thanda. The native title over the lake and surrounding region is held by the Arabana people.