A composite stiffener is provided with an integral conductive element extending longitudinally through an entire length of the composite stiffener to form a portion of an electrical ground/return system in a composite structure. The integral conductive element provides both structural strength and conductivity, and may be formed from graphite nanotube filaments, carbon nanofibers or nanoparticles, or a metallic filler material. The integral conductive element is disposed in a terminal portion of the composite stiffener and may include a terminal tab for connecting to the ground/return system.