An image sensor may include a photoelectric device configured to selectively absorb light associated with a first color of three primary colors, a semiconductor substrate stacked with the photoelectric device and including first and second photo-sensing devices configured to sense light associated with second and third colors of the three primary colors, respectively, a first color filter corresponding to the first photo-sensing device and configured to selectively transmit light of the first wavelength spectrum, a second color filter corresponding to the second photo-sensing device and configured to selectively transmit light associated with a mixed color of the first color and the third color, and a first insulating layer between the photoelectric device and the semiconductor substrate and corresponding to the second photo-sensing device, and configured to selectively reflect light of a part of visible light.