An image sensor includes a sensor substrate including a plurality of pixels configured to sense light; a color separation lens array including a plurality of pixel corresponding regions facing the plurality of pixels, wherein each pixel corresponding region of the plurality of pixel corresponding regions includes one or more nanoposts, and the one or more nanoposts are configured to form a phase profile that separates incident light for each wavelength, and to concentrate light in different wavelength bands on the plurality of pixels; and a filter array positioned between the sensor substrate and the color separation lens array, and including a plurality of transparent regions altematingly arranged with a plurality of filters corresponding to a single color.