A display device includes a display panel including a substrate and a plurality of display elements disposed on the substrate, and a diffraction panel including a plurality of diffraction patterns disposed on a path of light emitted from the plurality of display elements. The plurality of diffraction patterns are disposed in a first direction to have a first period, each of the plurality of diffraction patterns includes a first refractive layer, a second refractive layer disposed on the first refractive layer, and a third refractive layer disposed on the second refractive layer, and a refractive index of the second refractive layer is higher than a refractive index of the first refractive layer and a refractive index of the third refractive layer.