The present disclosure relates to an organic light-emitting diode: comprising a first electrode; a second electrode facing the first electrode; and a hole transport layer and a light-emitting layer disposed in that order between the first and the second electrode, wherein the light-emitting layer includes a host and a hole assistant material represented by the following Chemical Formula A, the hole assistant material having a highest occupied molecular orbital (HOMO) energy level lower in absolute value than that of the host.