A display device includes a substrate including a display area and a peripheral area outside the display area. A circuit unit is disposed in the display area and includes a semiconductor layer. An insulating layer is on the semiconductor layer. A conductive layer is connected to the semiconductor layer through a contact hole in the insulating layer. The conductive layer includes an underlayer including a metal nitride including a first metal. A display element is disposed on the circuit unit and includes a pixel electrode electrically connected to the conductive layer. A connection layer is disposed under the conductive layer. The connection layer corresponds to the contact hole and includes a second metal.