A light-emitting device including an organometallic compound, an electronic apparatus including the light-emitting device, and the organometallic compound, are provided. The light-emitting device also includes a first electrode, a second electrode facing the first electrode, and an interlayer between the two electrodes and including an emission layer. The HOMO energy level of the organometallic compound is configured such that the luminescence efficiency and lifespan of the light-emitting device may be enhanced or improved.