An organic light-emitting display (OLED) device includes: a lower substrate; an organic light-emitting element disposed on the lower substrate; an anti-oxidation layer covering the organic light-emitting element; an inorganic oxide encapsulation layer covering the anti-oxidation layer; a first organic layer covering the inorganic oxide encapsulation layer; and a first inorganic encapsulation layer covering the first organic layer. The anti-oxidation layer is configured to suppress the organic light-emitting element from being oxidized by oxygen (O2) plasma at least in a pixel area.