An apparatus and method for fabricating an organic light emitting diode display device are provided. The apparatus for fabricating an organic light emitting diode display device includes a chamber, a mask disposed in the chamber to mount a substrate on the upper surface thereof and having a certain pattern of openings, a deposition material source disposed under the mask and supplying a deposition material to the mask through the openings of the mask to form a layer on the substrate, and a holding unit pressing the substrate toward the mask. The holding unit includes a member that is capable of being deformed according to a deformed shape of the substrate such that the mask closely contacts the substrate.