An organic light emitting display device includes a panel driver and a display panel including a plurality of pixels having a pixel circuit, a first driving voltage terminal connected to the driving transistor, a light emitting element, a second driving voltage terminal connected to the light emitting element, and a capacitor connected between a gate and source electrode of the driving transistor, the panel driver to drive the pixel circuit in a data charging period in which a difference between a data and reference voltage is charged into the capacitor, and a light emitting period in which the driving transistor receives a first driving voltage from the first driving voltage terminal and is turned on according to the voltage charged into the capacitor during the data charging period, whereby a current is supplied to the light emitting element which thereby emits light.