The present technology relates to an imaging device and an electronic device which enable image capturing based on the global shutter system, without reducing the amount of saturated signal charge. Pixels each including a photoelectric conversion unit that converts light received thereon into electric charge, and a holding unit that holds the electric charge transferred from the photoelectric conversion unit, a floating diffusion that is shared among a plurality of the pixels, and that holds the electric charge transferred from the holding unit, and a boost line through which the floating diffusion is boosted are included. The present technology is applicable, for example, to an imaging device to capture images on the basis of a global shutter system.