An organic light emitting diode includes: a first electrode; a second electrode facing the first electrode; a light emission layer between the first electrode and the second electrode; an electron injection layer between the second electrode and the light emission layer; and a buffer layer between the electron injection layer and the second electrode, where the electron injection layer includes a dipolar material and a first metal, and the buffer layer includes a metal having a work function of 4.0 eV or less.