An organic light-emitting display device is provided. The device can include a display area having an organic light-emitting element on a lower substrate; a bezel area surrounding the display area; a transparent encapsulation unit having first and second encapsulation layers, and a first particle cover; and a first buffer layer. The first encapsulation layer can cover the display area and the bezel area. The first particle cover layer can cover the display area and a portion of the bezel area adjacent to the display area. The first buffer layer, apart from the first particle cover layer, can cover another portion of the bezel area. The second encapsulation layer, which covers the first particle cover layer and the first buffer layer, contacts the first encapsulation layer at a contact surface between the first particle cover layer and the first buffer layer.