An organic light-emitting diode (OLED) display and a method of manufacturing the same are disclosed. In one aspect, the method includes performing a first mask process of forming an active layer of a thin-film transistor (TFT) over a substrate and performing a second mask process of i) forming a gate insulating layer over the active layer and ii) forming a gate electrode of the TFT over the gate insulating layer. The method also includes performing a third mask process of i) forming an interlayer insulating layer over the gate electrode and ii) forming a contact hole in the interlayer insulating layer so as to expose a portion of the active layer and performing a fourth mask process of forming a pixel electrode over the interlayer insulating layer.