Provided is a display device in which a defect by external light reflection is minimized in a non-display area. The display device includes a display panel and a touch unit arranged on the display panel. The display panel may include: a substrate including a display area and a non-display area arranged around the display area; an insulator including a valley portion, the valley portion being defined as an opening arranged along an outer side of the display area in the non-display area; and a display unit arranged in the display area and including a light-emitting element electrically connected to a thin film transistor. The touch unit may include a reflection prevention unit that overlaps the valley portion and is configured to reduce reflectivity of external light.