An organic light emitting diode display includes a substrate, a semiconductor disposed on the substrate that includes a channel for each of a plurality of transistors and doping regions formed at both sides of each channel; a gate insulating layer disposed on the semiconductor that includes an insulating layer opening through which the doping regions of two different transistors are exposed; a gate electrode disposed on the gate insulating layer that overlaps each channel; an interlayer insulating layer disposed on the gate electrode that includes a first and second contact holes through which the doping regions exposed within the insulating layer opening are each exposed; and data wirings disposed on the interlayer insulating layer that are each connected to the doping regions. The interlayer insulating layer includes an organic layer, and the first and second contact holes each include a first side wall positioned within the insulating layer opening.