A display device includes a switching transistor, a driving transistor, a storage capacitor connected to the switching and driving transistors, and an organic light-emitting diode connected to the driving transistor. The driving transistor is connected to the switching transistor. The driving transistor includes a semiconductor layer having a channel region, first doped regions at sides of the channel region, and second doped regions doped with impurities of a concentration greater than the first doped regions. A first electrode layer is over an insulating layer, which covers the semiconductor layer. The electrode layer includes convex portions extending toward the first doped regions and covering an end of the channel region. At least one of the convex portions has a width greater than or equal to a width of the end of the channel region.