A display device includes: a substrate; a display element on the substrate; a capping layer on the display element; a first auxiliary layer on the capping layer; and a thin-film encapsulation layer on the first auxiliary layer, wherein the thin-film encapsulation layer comprises a (1-1)-th inorganic encapsulation layer on the first auxiliary layer and a (1-2)-th inorganic encapsulation layer on the (1-1)-th inorganic encapsulation layer, wherein a refractive index of the first auxiliary layer is smaller than a refractive index of the capping layer and a refractive index of the (1-1)-th inorganic encapsulation layer, and a refractive index of the (1-2)-th inorganic encapsulation layer is smaller than the refractive index of the (1-1)-th inorganic encapsulation layer.