An organic light-emitting display apparatus includes a thin film transistor including an active layer, gate, source and drain electrodes, a first insulating layer disposed between the active layer and the gate electrode, and a second insulating layer disposed between the gate electrode and the source and drain electrodes; a pad electrode including a first pad layer disposed on the same layer as the source and drain electrodes and a second pad layer disposed on the first pad layer; a third insulating layer covering the source electrode and the drain electrode and an end portion of the pad electrode; a pixel electrode including a semi-transmissive metal layer and disposed in an opening formed in the third insulating layer; and a fourth insulating layer having an opening formed in a location corresponding to an opening formed in the third insulating layer and covering the end portion of the pixel electrode.