Various embodiments of a miniaturized optical proximity sensor are disclosed. In one embodiment, an ambient light sensor and a light detector are mounted on first and second spacers, which in turn are mounted to a top surface of an integrated circuit die-attached to a substrate. An optically-transmissive infrared pass compound is molded over the ambient light sensor, the light detector, the integrated circuit, alight emitter and peripheral portions of the substrate. Next, an optically non-transmissive infrared cut compound is molded to over the optically-transmissive infrared pass compound to provide a miniaturized optical proximity sensor having no metal shield but exhibiting very low crosstalk characteristics.