An organometallic complex represented by Formula 1-1 or Formula 1-2 is provided: wherein in Formulae 1-1 and 1-2, descriptions of R1 to R7, X1, X2, Y1 to Y4, rings A, B, C, and a to e are understood by referring to the description provided herein. An organic light-emitting device includes a first electrode, a second electrode facing the first electrode, and an organic layer that is disposed between the first electrode and the second electrode and includes an emission layer, wherein the organic layer includes at least one organometallic complex represented by Formula 1-1 or Formula 1-2.