A photodetection element includes: a photoelectric conversion structure that contains a first material having an absorption coefficient higher than an absorption coefficient of monocrystalline silicon for light of a first wavelength, for which monocrystalline silicon exhibits absorption, and generates positive and negative charges by absorbing a photon; and an avalanche structure that includes a monocrystalline silicon layer, in which avalanche multiplication occurs as a result of injection of at least one selected from the group consisting of the positive and negative charges from the photoelectric conversion structure. The first material includes at least one selected from the group consisting of an organic semiconductor, a semiconductor-type carbon nanotube, and a semiconductor quantum dot.