Lake Disappointment (Kumpupirntily) is an ephemeral salt lake in Western Australia, which typically is dry except during very wet periods such as the 1900 floods and in many recent tropical wet seasons since 1967. It lies on the Tropic of Capricorn, due east of the mining town of Newman, Western Australia, and the Jigalong community. It is at the northern side of the Little Sandy Desert, and south of the Karlamilyi National Park. The Canning Stock Route passes down the western shores of the lake and the surrounds consist mostly of sand dunes.