A display device including: a substrate including a main area and a sub-area at a side of the main area; a thin-film transistor on the substrate and positioned in the main area; a first insulating layer on a gate electrode of the thin-film transistor; a light-emitting element on the first insulating layer, positioned in the main area, and electrically connected to the thin-film transistor; a plurality of pads on the first insulating layer and positioned in the sub-area; and a light-blocking layer overlapping the plurality of pads and located between the substrate and the first insulating layer.