Provided is an organic light emitting device including a first electrode, a second electrode facing the first electrode, an interlayer between the first electrode and the second electrode and including an emission layer, and a capping layer outside the first electrode or the second electrode. The emission layer includes a first emitter, the first emitter emits red light and includes iridium, a photoluminescence (PL) spectrum of the first emitter includes a first peak (Imax) having a maximum intensity and a second peak (I2nd) having a second highest intensity, and a ratio (I2nd/Imax) of an intensity of the second peak to an intensity of the first peak is less than or equal to 0.5. The capping layer includes an amine-fee compound.