Sodium molybdate (Na2MoO4) doped graphene oxide/polypyrrole nanocomposite (GO-PPy + Na2MoO4) was synthesized and considered as a multi-functional corrosion inhibitor container to be embedded into the epoxy coating. To ensure the decoration of GO surface by PPy nanoparticles and doping of molybdate ions into the GO-PPy structure, several analyses such as FT-IR, Raman, ICP-OES, zeta potential, FE-SEM/EDS, and TEM were used. The active-barrier anti-corrosion features of GO-PPy and GO-PPy + Na2MoO4 in 3.5 wt% NaCl solution were screened by EIS, salt spray, pull-off, and cathodic disbanding tests. Potentiodynamic polarization analyses showed 77% inhibition efficiency in the solution containing GO+PPy + Na2MoO4 compared to the blank solution. The GO-PPy + Na2MoO4 reinforced epoxy coating exhibited the highest impedance (log ׀Z׀10 mHz = 10.58 Ω·cm2, after 63 days) and the lowest delamination values (3.58%, after 63 days) in comparison with the pure epoxy coating (EP) (log ׀Z׀10 mHz = 6.1 Ω·cm2 and delamination value = 48.75%, after 63 days). The interaction of the NH bonds in the PPy chain with the oxide layer, and the formation of molybdate-containing compounds resulted in a considerable enhancement of the epoxy coating adhesion to the metal surface in the presence of GO-PPy + Na2MoO4.