An organic light-emitting device includes: a first electrode; a second electrode opposite the first electrode; an emission layer between the first electrode and the second electrode; a hole transport region between the first electrode and the emission layer; and an electron transport region between the emission layer and the second electrode, the electron transport region including an electron control layer, wherein the hole transport region includes at least one compound selected from a first compound represented by Formula 1 and a second compound represented by Formula 2, and the electron control layer includes a third compound represented by Formula 3: