Disclosed is an organic light emitting display device and a method of manufacturing the same. The organic light emitting display device includes the thin film transistor of the drive unit that has the activation layer formed in a structure where the first oxide semiconductor layer and the second oxide semiconductor layer are stacked, the thin film transistor of the pixel unit that has the activation layer formed of the second oxide semiconductor layer, and the organic light emitting diode coupled to the thin film transistor of the pixel unit. The thin film transistor of the drive unit has channel formed on the first oxide semiconductor layer having a higher carrier concentration than the second oxide semiconductor layer, having a high charge mobility, and the thin film transistor of the pixel unit has a channel formed on the second oxide semiconductor layer, having a stable and uniform functional property.