Provided is a foldable display device. The foldable display device includes a housing comprising a folding area, a first unfolding area adjacent to the folding area, and a second unfolding area adjacent to the folding area and under the first unfolding area; a display panel located at the first unfolding area and the second unfolding area that is capable of providing light through a first surface and a second surface opposite the first surface; a shutter layer on the display panel in the first unfolding area that controls whether light is transmitted; a window on the shutter layer; and a shielding layer located at the second unfolding area that is capable of blocking the light.