An organic light-emitting display device includes: a display panel including a plurality of pixels, each of the plurality of pixels including an organic light-emitting device configured to emit colored light; a gamma data generating unit configured to generate gamma data corresponding to received RGB data; a correction rate calculating unit configured to determine a luminance correction rate of each of the plurality of pixels based on the gamma data respectively corresponding to the plurality of pixels; and a correction value determining unit configured to determine a luminance correction value of a color displayed via each of the plurality of pixels.