The Ustyurt or Ust-Yurt (from Kazakh: Үстірт; Uzbek: Ustyurt; Turkmen: Üstyurt; Karakalpak: Ústirt — flat hill, plateau) is a transboundary clay desert shared by Kazakhstan, Turkmenistan, and Uzbekistan.

The plateau's semi-nomadic population raises camels, goats, and sheep.

The Ustyurt is located between the Dead Kultuk, Mangyshlak Peninsula and Kara-Bogaz-Gol of the Caspian Sea to the west, and the Aral Sea, Amudarya Delta and Sarygamysh Lake to the east.