A tandem white organic light emitting device with improved efficiency, voltage and lifetime includes a first electrode and a second electrode opposing each other, a charge generation layer formed between the first electrode and the second electrode, a first stack disposed between the first electrode and the charge generation layer, the first stack including a first light emitting layer emitting blue light, and a second stack disposed between the charge generation layer and the second electrode, the second stack including a second light emitting layer including one or more hosts doped with a phosphorescent dopant emitting light having a longer wavelength than blue light, wherein the charge generation layer includes an n-type charge generation layer doped with a metal and a p-type charge generation layer made of an organic material.