A display device including: a substrate element including a base layer, a circuit layer, and a device layer, the base layer forming a plane defined by a first direction and a second direction perpendicular to each other; an encapsulation element provided on the substrate element to seal the device layer; a sealing element provided along edges of the encapsulation element to connect the encapsulation and substrate elements to each other; an optical element provided on the encapsulation element; a window element provided on the substrate element; an adhesive element provided between the optical and window elements to connect the optical element to the window element; and a filling element provided between the window element and the substrate element, wherein the filling element is spaced apart from the optical element and the adhesive element, and is overlapped with the sealing element when viewed in a direction normal to the plane.