An image sensor and a method of manufacturing the same are provided. The image sensor includes a photoelectric conversion layer; a color filter disposed on the photoelectric conversion layer; a low refractive index layer disposed on the color filter; a beam splitter disposed within the low refractive index layer; and a lens layer disposed on the low refractive index layer and covering the beam splitter. The beam splitter extends in a diagonal direction of a pixel area of the color filter, in a plan view.