An organic light-emitting display apparatus including: a pixel including a first region realizing an image and a second region through which external light is transmitted, a driving circuit unit disposed in the first region, a wire area including a third region and a fourth region, a wire for transferring a signal to the driving circuit unit, a first electrode disposed in the first region and electrically connected to the driving circuit unit, a pixel defining layer disposed in the first region and including a first opening and a second opening, a second electrode disposed in the first region opposite the first electrode, an organic emission layer disposed between the first electrode and the second electrode, and an insulating structure disposed between the substrate and the pixel defining layer and including at least one insulating layer that includes a third opening corresponding to the second region and the fourth region.