The present technology relates to an imaging device, a camera module, and an electronic apparatus that make it possible to reduce a profile of the camera module and to enhance sensitivity. The imaging device includes: a semiconductor substrate in which a light receiving section is formed that includes a plurality of pixels performing photoelectric conversion; and a reinforcing member that is disposed on side of the light receiving section of the semiconductor substrate and includes an opening in which a part opposed to the light receiving section is opened. The present technology is applicable to, for example, an imaging device that captures an image, a camera module that focuses light to capture an image, an electronic apparatus equipped with a camera function, a vehicle control system that is mounted on a vehicle, an endoscopic surgery system that is used in an endoscopic surgery, and the like.