An organic light-emitting diode (OLED) display device includes a substrate, a first gate electrode on the substrate, a second gate electrode on the first gate electrode and at least partially overlapping the first gate electrode, a semiconductor pattern between the first gate electrode and the second gate electrode and at least partially overlapping the first and second gate electrodes, a connecting electrode on the second gate electrode and electrically connected to the semiconductor pattern, and a pixel electrode on the connecting electrode and electrically connected to the connecting electrode.