A composition includes a carbon nanotube (CNT)-infused metal fiber material which includes a metal fiber material of spoolable dimensions, a barrier coating conformally disposed about the metal fiber material, and carbon nanotubes (CNTs) infused to the metal fiber material. A continuous CNT infusion process includes: (a) disposing a barrier coating and a carbon nanotube (CNT)-forming catalyst on a surface of a metal fiber material of spoolable dimensions; and (b) synthesizing carbon nanotubes on the metal fiber material, thereby forming a carbon nanotube-infused metal fiber material.