An organic light emitting display device includes a folding part configured to be folded, and a flat part adjacent to the folding part. The folding part includes a first pixel. The flat part includes a second pixel. The first pixel includes a first organic light emitting diode, a first driving transistor and a first control transistor. The first driving transistor includes a first semiconductor pattern. The first control transistor includes a second semiconductor pattern. The second pixel includes a second organic light emitting diode, a second driving transistor and second control transistor. The second driving transistor includes a third semiconductor pattern. The second control transistor includes a fourth semiconductor pattern. At least one of the first or second semiconductor patterns includes an oxide semiconductor or a polycrystalline silicon, and each of the third and fourth semiconductor patterns includes the other of the oxide semiconductor and the polycrystalline silicon.