A scan driver and organic light emitting display device are disclosed. The organic light emitting display device includes a display panel, a data driver that supplies a data signal to the display panel, and a scan driver that supplies a scan signal to the display panel, the scan driver comprising a shift register and an inverter that inverts a scan signal output through the output terminal of the shift register and outputs the inverted scan signal, wherein the shift register and the inverter are connected to separate voltage lines through which a gate-low voltage is delivered.