A connector assembly involving a plug connector that incorporates a photoelectric conversion element that conducts optical/electrical and electrical/optical signal conversion, and an actuation device that drives said photoelectric conversion element, and a receptacle connector mated with said plug connector, with the plug connector and the receptacle connector being electrically connected through mutual contact between terminals, wherein, in the plug connector, the front end side of a fiber optic cable used for optical signal transmission is connected to the rear end side of said plug connector and extends from the rear, lateral terminals are arranged in each of a pair of lateral edge portions that extend in the forward-backward direction, while end terminals are arranged in a front end edge portion 34 that extends perpendicular to the forward-backward direction.