An organic light emitting diode (OLED) display is disclosed. In one aspect the display includes a display panel having first through fourth pixels and a scan driving unit that outputs a scan signal to the display panel. The display also includes a data driving unit that alternately outputs a first data signal for the first pixels and a second data signal for the second pixels to the display panel, alternately outputs a third data signal for the third pixels and a fourth data signal for the fourth pixels to the display panel, and begins outputting the first and third data signals before one horizontal period begins The display further includes a demultiplexing unit that alternately applies the first and second data signals to the first and second pixels and the third and fourth data signals to the third and fourth pixels.