Disclosed herein is an organic light emitting display. The organic light emitting display is configured to include: a first transistor that receives a data signal from a data line in response to a scan signal from a scan signal line; a first capacitor that is charged with voltage corresponding to the data signal; a driving transistor that controls driving current supplied from a first power supply by corresponding to a voltage value charged in the first capacitor; a second transistor that connects or blocks the driving current transmitted through the driving transistor in response to an emission control signal from an emission control line; an organic light emitting diode that is connected between the second transistor and a second power supply and generates light corresponding to the driving current supplied from the driving transistor; and a reverse bias voltage applying module that reverses the polarity of the voltage supplied to the driving transistor simultaneously with applying reverse bias voltage to the organic light emitting diode in response to a reverse bias applying signal.