A display device includes: a substrate including a first pixel region, at least one second pixel region having a smaller area than the first pixel region, the at least one second pixel region being disposed adjacent to the first pixel region, and a peripheral region surrounding the first pixel region and the second pixel region; first and second pixels respectively provided in the first and second pixel regions; first and second lines respectively connected to the first and second pixels; a dummy line connected to one of the first and second lines to extend to the peripheral region; and a first dummy part including a dummy pixel connected to the dummy line in the peripheral region.