An organic light emitting diode (OLED) and an organic light emitting device comprising the OLED (e.g., a display device or a lighting device) are described. The OLED can include a first blue emitting material layer including a first host, and a second blue emitting material layer including a second host, disposed between two electrodes. The OLED includes two blue emitting material layers so that an exciton recombination zone is distributed within the blue emitting material layers irrespective of current density or gradation. As the amount of non-emitting excitons accumulated outside of the emitting material layers is minimized, the driving voltage of the OLED can be lowered, and the luminous efficiency and the luminous lifespan of the OLED can be improved.