An organic light emitting display is capable of reducing variation in power transmitted to pixels to reduce or prevent non-uniformity of brightness from being generated. The organic light emitting display includes a pixel including a red sub pixel, a green sub pixel, and a blue sub pixel and first pixel power source lines for supplying a first pixel power from a first pixel power source to the red sub pixel, the green sub pixel, and the blue sub pixel, wherein the first pixel power source lines coupled to at least two different color sub pixels of the red, green and blue sub pixels have different widths. The first pixel power source lines have widths that may correspond to a voltage drop of the first pixel power source or may correspond to deterioration of the respective sub pixels to which they are coupled.