A holographic optical information playback apparatus for playing information that is recorded on a recording medium in a form of interference fringes is provided with a two-dimensional photoreceptor array which receives a two-dimensional array of light spots that is diffracted at the recording medium due to application of reference light onto the medium, and outputs a playback signal including information recorded on the recording medium. The two-dimensional photoreceptor array has a photoreceptor section in which plural photoreceptor cells for detecting the intensities of received lights are arranged so that a photoreceptive area corresponding to the light spot array is formed, and assigns plural photoreceptor cells are assigned to each light spot in the light spot array according to the irradiation position of the light spot array, whereby the light intensity of one light sport is detected using the output signals from the plural photoreceptor cells.