Abstract: An optical proximity sensor for optically detecting an object within a predetermined detection volume. More specifically, an optical proximity sensor is disclosed having an illuminator assembly including an illuminator lens (55) and a plurality of light-emitting diodes (53) located at first predetermined positions along the focal plane (54) of the illuminator lens (55). A detector assembly including a detector lens (65) and a plurality of photodiodes (60) located at second predetermined positions along the focal plane of the detector lens (65) is also provided. The two lenses are spaced apart a predetermined distance in accordance with the configuration of the light-emitting diodes (53) and the photodiodes (60) in order to define a predetermined detection volume. Each light-emitting diode has a corresponding photodiode, and their relative positions on their respective focal planes determine the detection volume defined by their overlapping fields of view.