A display device includes a display panel that is foldable based on a folding line extending in a first direction. A support member is on a first surface of the display panel and includes first and second non-folding parts, a folding part disposed therebetween which is stretched when the display panel is folded and a groove disposed on the folding part. The folding part includes slits and bars disposed between the slits. The support member includes fiber yarns extending in the first direction and fiber yarns extending in a second direction crossing the first direction. The fiber yarns extending in the first direction and the fiber yarns extending in the second direction are alternately stacked along a thickness direction of the support member. The slits and the fiber yarns on an upper surface of the folding part exposed by the groove have a same extension direction as each other.