A foldable display device includes a display module including a first non-folding portion, a second non-folding portion, and a first folding portion between the first non-folding portion and the second non-folding portion, a first support member on a lower surface of the display module, the first support member including a first support portion supporting the first non-folding portion, a second support portion supporting the second non-folding portion, and a first opening pattern overlapping the first folding portion, and including a glass material, and a second support member under the first support member and supporting the display module.