An organic light emitting display device includes: a substrate having a sub-pixel circuit region including a driving transistor region; an active pattern in the sub-pixel circuit region on the substrate, and including a bent portion having a first length in the driving transistor region, and a straight portion adjacent to the bent portion in the driving transistor region and having a second length shorter than the first length in the driving transistor region; and a sub-pixel structure on the active pattern. Accordingly, when the organic light emitting display device is driven at a low gray level, the organic light emitting display device can improve the low gray-level spot and the crosstalk while relatively reducing the power consumption.