Provided is an organic light-emitting display apparatus. The organic light-emitting display apparatus includes a first substrate; an organic light-emitting device disposed on the first substrate; and a thin film comprising at least one perovskite compound represented by Formula 1 disposed on the organic light-emitting device. T the thin film is positioned in a traveling direction of light emitted from the organic light-emitting device: [A][B1nB2(1-n)][X]3   A is at least one monovalent organic-cation, at least one monovalent inorganic-cation, or a combination thereof. B1 and B2 are each independently at least one divalent inorganic-cation. n is a real number satisfying 0