The present disclosure relates to a foldable display apparatus. A foldable display includes: a display layer disposed on the top surface of a flexible substrate; an encapsulation layer covering the display layer; and a back plate disposed under the bottom surface of the flexible substrate, the back plate includes: a reference plane; a first folding plane disposed at one side of the reference plane; a second folding plane disposed at another side of the reference plane; a first bending part disposed between the reference plane and the first folding plane and having a first bending radius; and a second bending part disposed between the reference plane and the second folding plane and having a second bending radius, wherein the first folding plane is thinner than the reference plane.