An OLED display including a substrate main body; a first gate electrode and a second semiconductor layer; a gate insulating layer on the first gate electrode and the second semiconductor layer; a first semiconductor layer and a second gate electrode overlying the first gate electrode and the second semiconductor layer, respectively; etching stopper layers contacting portions of the first semiconductor layer; an interlayer insulating layer on the first semiconductor layer and the second gate electrode and including contact holes exposing the plurality of etching stopper layers, respectively; a first source electrode and a first drain electrode on the interlayer insulating layer and the contact holes being indirectly connected to the first semiconductor layer via the etching stopper layers or directly connected to the first semiconductor layer; and a second source electrode and a second drain electrode on the interlayer insulating layer being connected to the second semiconductor layer.