Provided are an imaging element, an imaging device, an endoscope, and an endoscope system, with which a same-phase fluctuation component from a power supply and superposed on an image signal can be removed. A first chip (21) is equipped with: a photoreception unit (23) having multiple photoelectric conversion elements that are arranged as a two-dimensional matrix, and that receive light from the outside and store a charge in accordance with the amount of light; an imaging signal generation unit (240) that generates an imaging signal by converting the charges stored by the multiple photoelectric conversion elements to a voltage; and a reference signal generation unit (248) that generates a reference signal having a fluctuation component of the same phase as the imaging signal generated by the imaging signal generation unit (240).