In order to provide an optical sensor that can accurately sense a direction of movement of an object to be sensed even in a case where disturbance light is present, an optical sensor of the present invention includes: a light-emitting element; a circularly-segmented light-receiving element group (RDPD), including light-receiving elements circularly provided at edges of a region on which reflected light from an object to be sensed reflecting light emitted by the light-emitting element is incident, for generating respective photocurrents upon receiving the reflected light; and a gesture circuit section for sensing a direction of movement of the object to be sensed upon receiving the photocurrents generated by the light-receiving elements included in the circularly-segmented light-receiving element group (RDPD).