An organic light-emitting diode includes a first electrode, a first light-emitting unit (EL unit) disposed on the first electrode and including a first organic light-emitting layer, a first charge generating layer on the first EL unit, a second EL unit disposed on the first charge generating layer and including a second organic light-emitting layer, a third organic light-emitting layer and a fourth organic light-emitting layer, a second charge generating layer on the second EL unit, a third EL unit disposed on the second charge generating layer and including a fifth organic light-emitting layer, and a second electrode on the third EL unit. A dopant concentration of the third organic light-emitting layer is greater than a dopant concentration of the fourth organic light-emitting layer. An organic light emitting display device can include the organic light-emitting diode.