An organic light emitting diode (OLED) display device and a method of fabricating the OLED display device, the OLED display device includes a substrate including an emission region and a non-emission region, a black matrix disposed in a region excluding a part of the emission region, a buffer layer disposed on the entire surface of the substrate, a semiconductor layer disposed on the buffer layer in the non-emission region, a gate electrode disposed on the semiconductor layer, a gate insulating layer insulating the semiconductor layer from the gate electrode and formed on the entire surface of the substrate, a first electrode formed on the gate insulating layer in the emission region, source and drain electrodes electrically connected with the semiconductor layer and the first electrode, an interlayer insulating layer insulating the source and drain electrodes from the gate electrode and opening a part of the first electrode, a pixel defining layer opening a part of the first electrode and disposed on the entire surface of the substrate, an organic layer disposed on the first electrode, and a second electrode disposed on the entire surface of the substrate. Here, the first electrode includes a transparent conductive oxide layer.