An organic light emitting display device includes a display unit including a plurality of data lines, a plurality of scan lines, and pixels at crossing regions of the data lines and scan lines, wherein the plurality of data lines are arranged into a plurality of groups; a data driver for supplying data signals to the data lines; a first demultiplexer at a first side of the display unit for associating the groups to first corresponding output channels of the data driver, and for coupling the output channels to the data lines in the first corresponding groups in accordance with control signals; a second demultiplexer at a second side of the display unit opposite the first side for associating the groups to second corresponding output channels of the data driver, and for coupling the output channels to the data lines in the second corresponding groups in accordance with the control signals.