A method of fabricating an organic light emitting diode display device, includes forming a thin film transistor on a first substrate, forming an organic light emitting element electrically connected to the thin film transistor, on the first substrate, forming a black matrix, in which openings are formed, on one surface of a second substrate opposite to the first substrate, forming a color filter layer in the openings, forming a transparent insulation layer having a first surface and a second surface opposing the first surface on the second substrate, with the first surface of the transparent insulating layer in direct contact with the color filter layer, forming a plurality of optical patterns at the second surface of the transparent insulation layer, and attaching the first substrate and the second substrate such that the second surface of the transparent insulating layer is closer to the thin film transistor than the first substrate.