An organic light-emitting display device displays a grayscale level by time-dividing each frame into N sub-frames, the organic light-emitting display device including: a plurality of pixels arranged in a matrix; a plurality of scan lines to be provided with a plurality of scan signals to turn on the plurality of pixels; and a plurality of data lines to be selectively provided with a plurality of data voltages or a plurality of sensing voltages to be applied to a number of the pixels that are turned on by each of the plurality of scan signals, wherein the scan signals are provided to N scan lines (where N is a natural number greater than 1) that are randomly selected from among the plurality of scan lines at intervals of a sub-horizontal period.