An organic light emitting display, suitable for a high quality and high resolution display device, rapidly charges a data voltage using a voltage programming technique, after compensating for a deviations in the threshold voltage and mobility of a driving transistor using a current programming technique. The organic light emitting display includes: a data line supplying a data signal; a scan line supplying a scan signal; a first switching element, electrically coupling its control electrode to the scan line, transferring the data signal supplied from the data line; a driving transistor, electrically coupling its control electrode to the first switching element, controlling a driving current of a first voltage line; a first capacitive element electrically coupled between the first switching element and the control electrode of the driving transistor; an Organic Light Emitting Diode (OLED), electrically coupled between the driving transistor and a second power voltage line, displaying an image by a current supplied from the driving transistor; and a fourth switching element compensating for deviations of characteristics of the driving transistor by supplying a current of the first current line to the driving transistor.