An organic light emitting diode (OLED) display includes a display panel including data lines, scan lines crossing the data lines, and pixels which each include an organic light emitting diode and are arranged in a matrix form, a power generator which is enabled in a normal mode to generate a high potential power voltage for driving the display panel and is disabled in a low power mode, and a panel driving circuit which drives the data lines and the scan lines, disables the power generator in the low power mode to cut off an output of the power generator, and supplies an internal power less than the high potential power voltage to the display panel to reduce the high potential power voltage in the low power mode.