An organic light emitting display device including: a substrate; an active layer formed on the substrate; a first insulation film disposed on the substrate to cover the active layer; a transistor including a gate electrode disposed at a location corresponding to the active layer with the first insulation film in between, and source and drain electrodes electrically connected to the active layer; a first electrode layer disposed on the substrate and electrically connected to any one of the source and drain electrodes of the transistor; a second electrode layer formed on the first electrode layer; an organic light emitting layer disposed between the first electrode layer and the second electrode layer; and a light reflecting unit covering a side and a part of top of the first electrode layer.