Disclosed is an organic light emitting display device including a pixel connected to a data line, a gate line group, and a reference line. The pixel includes an organic light emitting diode (OLED), a driving transistor configured to control a current flowing in the OLED, a first switching transistor configured to selectively supply a data voltage to a first node, a second switching transistor configured to selectively supply an initial voltage to a second node, a third switching transistor configured to selectively connect a third node to the reference line, a fourth switching transistor configured to selectively connect the first node to the third node, a first capacitor connected between the first and second nodes to store a threshold voltage of the driving transistor, and a second capacitor connected between the first and third nodes to store the data voltage supplied through the first switching transistor.