An organic light-emitting display apparatus includes: a substrate; a first electrode on the substrate; an organic emission layer on the first electrode; a second electrode on the organic emission layer; and a sealing layer including a capping film, a first inorganic film, a first organic film, a second inorganic film and a hydroxyquinoline-based blocking film between the second electrode and the first organic film that are sequentially stacked on the second electrode, the hydroxyquinoline-based blocking film comprising a hydroxyquinoline-based compound.