In a connector assembly in which a connector that includes an insulator, signal terminals and a ground terminal which are disposed on the insulator, and a shell having conductivity and a mating connector that includes a mating insulator, mating signal terminals and a mating ground terminal which are disposed on the mating insulator, and a mating shell having conductivity are fitted to each other, the shell includes a frame-like portion that is an outer shell of the connector and an extension portion that is extended from the frame-like portion toward an inside of a frame of the frame-like portion, the ground terminal is integrally formed with the extension portion so that the ground terminal is elastically deformable, and the insulator is fixed and held in the shell by pressing a press-fitting portion included in the extension portion into a press-fitted portion of the insulator.