A display device includes: a substrate including a display area and a non-display area; a transistor and a light emitting element, which are disposed on the display area; a pad portion disposed in the non-display area, where the pad portion includes a first metal pattern; and a printed circuit board or a data driver, which is connected with the pad portion. The transistor includes a semiconductor layer disposed on the substrate and a source electrode or a drain electrode which is electrically connected with the semiconductor layer. The source electrode or the drain electrode includes a first layer including a first metal, a second layer including a second metal, and a third layer including the first metal, where the first metal pattern includes the first metal, and is connected with the printed circuit board or the data driver.