A foldable display device includes a display panel which includes a folding area, a first non-folding area disposed adjacent to a first side of the folding area, and a second non-folding area disposed adjacent to a second side of the folding area opposite to the first side of the folding area, and a panel support member which is disposed on a surface of the display panel and in which a plurality of slits extending in a first direction is defined. The panel support member includes a first layer which has a first fiber yarn extending in a second direction intersecting the first direction, a second layer which has a second fiber yarn extending in the first direction, and a third layer which has a third fiber yarn extending in the second direction.