A display apparatus, and a light guide plate (LGP) of the display apparatus are provided. The LGP may include a first light guide segment and a second light guide segment that are alternately arranged in a first direction. The first light guide segment and the second light guide segment may be separated from each other by a light barrier. Light guided and output in the LGP may be diffused in one direction by an anisotropic diffuser. The first light guide segment may be configured to guide light from a first light source used to generate a two-dimensional (2D) image. The second light guide segment may be configured to guide light incident from a second light source used to generate a three-dimensional image.