A light-emitting device includes: a substrate; a cathode on the substrate; an anode on the cathode; and an organic layer arranged between the cathode and the anode and including an emission layer. The organic layer includes: an electron transport region between the emission layer and the cathode; and a hole transport region between the emission layer and the anode, wherein the hole transport region includes a first compound including a first repeating unit represented by Formula 1, a second compound represented by Formula 2, a fifth compound represented by Formula 5, or any combination thereof, wherein Formulas 1, 2, and 5 are respectively the same as described herein.