An organic light emitting display device includes a substrate, a plurality of unit pixels on the substrate, each unit pixel including a first region that emits light and a second region that transmits external light, thin film transistors (TFTs) disposed in the first region of each unit pixel, first electrodes disposed in the first region of each unit pixel, each first electrode being electrically connected to one of the TFTs, a second electrode facing the first electrodes, and commonly disposed in the unit pixels, and an organic layer interposed between the first electrodes and the second electrode, and including an emissive layer. With respect to two adjacent pixels of the plurality of unit pixels, the first region and the second region in one unit pixel are symmetrical with the first region and the second region in another adjacent unit pixel, and the second regions are connected to each other.