Graphene semiconductor device, a method of manufacturing a graphene semiconductor device, an organic light emitting display and a memory, include forming a multilayered member including a sacrificial substrate, a sacrificial layer, and a semiconductor layer deposited in sequence, forming a transfer substrate on the semiconductor layer, forming a first laminate including the transfer substrate and the semiconductor layer by removing the sacrificial layer to separate the sacrificial substrate from the semiconductor layer, forming a second laminate by forming a graphene layer on a base substrate, combining the first laminate and the second laminate such that the semiconductor layer contacts the graphene layer, and removing the transfer substrate.