A display device includes a substrate, an encapsulation portion on the substrate, a seal portion between the substrate and the encapsulation portion, and at least one dummy seal portion around the seal portion. The substrate and the encapsulation portion at least partially overlap each other in a first direction perpendicular to a surface of the substrate. The dummy seal portion is, when viewed in the first direction, arranged in an area between an edge of the seal portion and a boundary line of an overlapping area of the substrate and the encapsulation portion.