Low alloy steels (LASs) are widely used in various sectors, such as aerospace, automobile, nuclear, petroleum, and shipping. The microstructure of LAS primarily consists of the ferritic phase, which is known to demonstrate a high degree of susceptibility to corrosion and hydrogen embrittlement in harsh environments. The wear performance of LAS is very poor in certain applications, such as railway undercarriages and aircraft landing gears. Therefore, surface modification techniques are extensively utilized to withstand corrosion, hydrogen embrittlement, and wear. In the present study, the cathodic plasma electrolytic nitriding (c-PEN) technique was used to modify a low alloy ferritic steel (2.25Cr-1Mo) surface and assess the effect of c-PEN layer on corrosion, hydrogen permeation, and tribological behavior of the steel. The surface morphology and phase composition of the c-PEN treated surface were analyzed; it was found that the c-PEN treated surface exhibits a globular network morphology of iron nitride and expanded ferrite. The potentiodynamic polarization results showed that the c-PEN treatment created an electrochemically noble surface compared to the untreated steel. Next, electrochemical hydrogen permeation experiments carried out on the nitrided surface exhibited a noticeable drop in hydrogen permeability, diffusivity, and reversible trap density of the steel. Furthermore, based on nanomechanical and tribological characterization, the c-PEN treatment was found to create a noticeably harder and wear-resistant surface. Overall, these findings demonstrate the applicability of c-PEN treatment to create a multi-functional coating for low alloy steels that can assist in mitigating the effect of various harsh environments.