In this research, graphene oxide (GO) functionalized with 3-amino-1, 2, 4-triazole-5 thiol (ATT) [fGO] has been synthesized for the achievement of a high protection performance of epoxy coatings with enhanced mechanical properties. A novel combination of fGO/epoxy composite coating will be a promising application for the corrosion protection of steel. The corrosion protection evaluation of fGO-grafted epoxy composite coatings on mild steel is investigated using electrochemical impedance spectroscopy (EIS) and scanning electrochemical microscopy (SECM). EIS revealed high film resistance, charge transfer resistance and low capacitance for the fGO-grafted epoxy-coated mild steel. SECM analysis showed less current distribution (0.5-2.5 I/nA) at the scratched surface of fGO-grafted composite coatings compared to neat epoxy coatings (2-10 I/nA) on mild steel. The presence of sulfur and nitrogen atoms in the fGO facilitates the enhanced corrosion protection performance of epoxy-fGO-coated mild steel. Mechanical properties of the coatings were also found to be improved in the presence of modified GO particles as evidenced by hardness test and pull-out adhesion test.