A facile, efficacious, and practical multifunctional paradigm has been developed for imparting corrosion resistance to low carbon steel based on the direct in situ growth of carbon nanofibers (CNF) onto steel substrates followed by infusion of a polymer matrix. The polymer layer locks into place between the nanofibers, simultaneously preventing coating delamination and imparting unprecedented surface passivation properties. The novel hybrid nanocomposite coatings maintain structural integrity even after 30 days of exposure to saline corrosive environments, indicating unprecedented corrosion protection derived from the redox-active nature of the CNF fillers and their excellent dispersion within the polymer matrix. These remarkable coating properties are further enhanced by the strong adhesion of the host polymer to the underlying steel substrate.