An organic light emitting display device includes a substrate, a lower electrode, a light emitting layer, an upper electrode, and a light guide structure. The substrate includes a sub-pixel region and a transparent region. The lower electrode is disposed in the sub-pixel region on the substrate. The light emitting layer is disposed on the lower electrode, and includes an organic emission layer. The upper electrode is disposed on the light emitting layer. The light guide structure is disposed on the upper electrode, and partially overlaps the organic emission layer that is located at the sub-pixel region and the substrate that is located at the transparent region in a plan view.