A light-emitting device including a first electrode, a hole transport region disposed on the first electrode, a first light-emitting layer disposed on the hole transport region and emitting light of a first wavelength, a second light-emitting layer disposed on the hole transport region and emitting light of a second wavelength different from the first wavelength, an electron transport region disposed on the first light-emitting layer and the second light-emitting layer, and a second electrode disposed on the electron transport region, wherein the second light-emitting layer includes a first sub light-emitting layer including a first host and a first dopant and emitting the light of the second wavelength, and a second sub light-emitting layer including a second host different from the first host and a second dopant and emitting the light of the second wavelength. Accordingly, a luminous efficiency and device lifetime of the light-emitting device may be improved.