A display device includes a substrate, a display unit disposed over the substrate, and an encapsulation layer sealing the display unit. The display unit includes a thin film transistor, a display element electrically connected to the thin film transistor, a protection layer, and a planarization layer. The protection layer and the planarization layer are disposed between the thin film transistor and the display element. The display unit includes a display area and a non-display area outside the display area. The non-display area includes a voltage line. The planarization layer includes a dividing region dividing the planarization layer into a center portion and an outer portion. The dividing region surrounds the display area. The voltage line is partially disposed in the dividing region. The protection layer at least covers the sides of the voltage line disposed in the dividing region.