An organic light emitting display device includes substrates, connection substrates, sub-pixel structures, a thin film encapsulation structure, and a reflection pattern. The substrates each has a pixel region, and is spaced apart from each other. The pixel region includes sub-pixel regions and reflective region surrounding the sub-pixel regions. The connection substrates connect adjacent substrates among the substrates. The sub-pixel structures are disposed in the sub-pixel regions on the substrates each. The thin film encapsulation structure is disposed on the sub-pixel structures. The reflection pattern is disposed in the reflective region on the thin film encapsulation structure.