Disclosed are an organic light-emitting device and an organic light-emitting display device capable of improving reliability thereof. The organic light-emitting device or the organic light-emitting display device includes an organic encapsulation layer disposed on a light-emitting element, and the organic encapsulation layer includes a first organic encapsulation layer disposed on an inorganic encapsulation layer and a second organic encapsulation layer disposed so as to surround the first organic encapsulation layer and including a moisture-absorbent material. As such, it is possible to achieve a reduction in cost and to prevent moisture or oxygen from being introduced from the outside into the side surface of the organic light-emitting device.