A display device includes: a display panel in which a first panel region, a bending region, and a second panel region are arranged along a first direction; a support layer below the first panel region of the display panel, wherein the bending region of the display panel is bent toward a lower portion of the support layer; a portion of the support layer is between the first panel region and the second panel region; a first alignment mark in the first panel region; and a first alignment opening overlapping the first alignment mark in the support layer, wherein in a thickness direction of the display panel, the first alignment opening is spaced apart from the second panel region, the first alignment opening is spaced apart from an edge of the support layer, and the first alignment opening is completely surrounded by the support layer.