An organic light emitting display device including a thin film transistor including an active layer, a gate electrode, a source electrode, a drain electrode, a source electrode top layer on the source electrode and a drain electrode top layer on the drain electrode, a first insulating layer between the active layer and the gate electrode, and a second insulating layer between the gate electrode and the source and drain electrodes; a pad electrode including a first pad layer at the same level as the source electrode and a second pad layer on the first pad layer and at the same level as the source and drain electrode top layers; a third insulating layer covering end portions of the source, drain, and pad electrodes and including an organic insulating layer; and a pixel electrode in an opening formed in the third insulating layer and including a semi-transmissive metal layer.