A display device includes: a display panel; and a support plate under the display panel, and including a first non-folding portion, a folding portion, and a second non-folding portion, which are located along a first direction. The folding portion includes: a plurality of openings; and branches between the openings. An area ratio of the openings to the branches is greater at a portion of the folding portion adjacent to at least one of the first or second non-folding portions than at a center of the folding portion.