An organic light emitting display device includes a substrate including a sub-pixel region and a transparent region, a first semiconductor element in the sub-pixel region on the substrate, a second semiconductor element overlapping at least a portion of the sub-pixel region on the substrate, and is spaced apart from the first semiconductor element, a first lower electrode disposed in the sub-pixel region on the first semiconductor element and electrically connected to the first semiconductor element, a second lower electrode disposed in the transparent region on the substrate and electrically connected to the second semiconductor element, a first light emitting layer on the first lower electrode, a second light emitting layer on the second lower electrode, and an upper electrode on the first and second light emitting layers where second lower electrode has a thickness that is less than a thickness of the first lower electrode, and transmits a light.