Abstract: A foldable display device is provided, which includes a first middle frame and a second middle frame for supporting a flexible display panel. A first surface of a first planar support member of the first middle frame that faces the display panel extends toward a second planar support member, and a second surface of the second planar support member of the second middle frame that faces the display panel extends toward the first planar support member. Accordingly, the distance between the first surface of the first planar support member and the second surface of the second planar support member is reduced. Therefore, when the display panel expands, the bending region of the display panel can be effectively supported by the first planar support member and the second planar support member. In this way, the bending region can have better flatness when the display panel expands.