This study investigates using a novel solvent-free, UV LED-curable coating as a robust corrosion protection solution for the inner surface of steel pipelines. The properties of the UV-cured film were characterized in terms of reactivity, thermomechanical properties, and adhesion to metal substrates. The coating was then applied on the inside of steel pipelines and cured using a patented UV LED lamp specifically designed to fit in confined spaces. Finally, electrochemical impedance spectroscopy (EIS) characterization and accelerated cyclic electrochemical technique (ACET) were performed on the coated pipes to study the corrosion protection properties of the coating, both with and without the addition of inorganic fillers. The results were compared to a commercially available thermally cured coating. It was found that the UV-cured coating confers high barrier properties, effectively preventing liquid penetration even under elevated temperature conditions. Furthermore, the corrosion protection performance in harsh environments was comparable to and, in some cases, higher than standard epoxy linings.