The present technology relates to a solid-state imaging device capable of inhibiting peeling of a fixed charge film while inhibiting dark current, a method of manufacturing the same, and an electronic device. A solid-state imaging device provided with a semiconductor substrate in which a plurality of photodiodes is formed, a groove portion formed in a depth direction from a light incident side for forming an element separating unit between adjacent photoelectric conversion elements on the semiconductor substrate, a first fixed charge film formed so as to cover a surface of a planar portion on the light incident side of the semiconductor substrate, and a second fixed charge film formed so as to cover an inner wall surface of the groove portion formed on the semiconductor substrate is provided. The present technology is applicable to a backside illumination CMOS image sensor, for example.