A display device includes a substrate including a display area and a pad area, a pixel structure disposed on the display area, a pixel insulating layer disposed on the pad area and having a first opening, and a pad electrode structure including a signal electrode disposed in the first opening, a connection electrode disposed on the signal electrode, and a pad electrode disposed on the connection electrode. An upper surface and a side surface of the signal electrode come into direct-contact with a lower surface of the connection electrode. An upper surface and a side surface of the connection electrode come into direct-contact with a lower surface of the pad electrode.