An organic light-emitting diode including: a first mixed layer between an emission layer and a first electrode and including first and second compounds; a second mixed layer between the emission layer and the first mixed layer and including third and fourth compounds; a first charge generation layer between the first mixed layer and the first electrode and including the first and second compounds and a first charge generation material; a second charge generation layer between the first mixed layer and the second mixed layer and including the third and fourth compounds and a second charge generation material; and a buffer layer between the emission layer and the second mixed layer, the first and the third compounds are each independently a compound represented by Formula 1 below, and the second compound and fourth compounds are each independently a compound represented by Formula 2 below: