Lake Disappointment 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.
Lake Disappointment was named by the explorer Frank Hann in 1897. Hann was in the area exploring the east Pilbara, around Rudall River. He noticed creeks in the area flowed inland, and followed them, expecting to find a large fresh water lake. To his disappointment, the lake turned out to be salt, and subsequently it was named Lake Disappointment. The lake is home to many species of waterbirds.