A complex spatial light modulator and a three-dimensional (3D) image display apparatus including the complex spatial light modulator are provided. The complex spatial light modulator includes: a spatial light modulator that modulates a phase of light; a prism array including a plurality of prism units, each of the plurality of prism units including a first prism surface and second prism surface, where light from the spatial light modulator is incident on the prism array; and a polarization-independent diffracting element that diffracts light that has passed through the prism array.