An organic light-emitting device includes a first electrode and a second electrode, a first organic emission layer disposed between the first electrode and the second electrode and comprising a first dopant, and a second organic emission layer disposed between the first electrode and the second electrode and comprising a second dopant. The maximum luminescence wavelength of the first dopant may be larger than the maximum luminescence wavelength of the second dopant. The difference between the maximum luminescence wavelength of the first dopant and the maximum luminescence wavelength of the second dopant is 10 nm or less.