An organic light emitting display is capable of reducing or minimizing the number of wiring lines to improve an aperture ratio. The organic light emitting display includes scan lines and data lines that cross each other at crossing regions, sub pixels located at the crossing regions that display an image in accordance with an amount of current that flows from a first power source to respective organic light emitting diodes in the sub pixels, and first power source lines that are parallel to the data lines, each of the first power source lines corresponding to at least two of the data lines. The first power source lines include a first group of the first power source lines that receive the first power source and a second group of the first power source lines that receive a second power source.