An organic light-emitting display device having an integrated thin-film solar cell includes a substrate, a display disposed in a first area on the substrate to display images and including a first thin-film layer, and a thin-film solar cell disposed in a second area on the substrate to receive sunlight and generate electricity to drive the display and including a second thin-film layer, in which the first thin-film layer and the second thin-film layer include the same thin-film layer extending from the first area to the second area.