A an organic light-emitting display apparatus, including a first substrate, a display unit having a plurality of organic light-emitting devices that is formed on the first substrate, a second substrate disposed on the display unit, and a filler included between the first substrate and the second substrate. The organic light-emitting device includes a first electrode formed on the first substrate, an intermediate layer that is disposed on the first electrode and includes an organic emission layer, and a porous second electrode disposed on the intermediate layer.