A display device includes: a substrate that includes an opening and a display area that surrounds the opening; a plurality of grooves formed in the substrate between the opening and the display area; a display element layer on the substrate and that includes a plurality of display elements in the display area; a thin-film encapsulation layer disposed on the display element layer, the thin-film encapsulation layer including a first inorganic encapsulation layer, an organic encapsulation layer, and a second inorganic encapsulation layer which are sequentially stacked; a planarization layer disposed over the plurality of grooves and that includes an organic insulating material, wherein the planarization layer is disposed over the second inorganic encapsulation layer, and the organic encapsulation layer is disposed below the second inorganic encapsulation layer.