Dual phase steel has been widely used in the automotive industry to produce lighter weight vehicles to meet stringent safety and fuel economy regulations. One potential concern with dual phase steel is galvanic corrosion when it is exposed to a corrosive environment. In dual phase steel, the dissimilarity in chemical composition and lattice structure could induce different corrosion potentials between the ferrite and martensite phases. As a result, microscopic galvanic couplings could be formed between ferrite grains and their neighboring martensite grains. In this study, the corrosion behaviors of three commercial steel grades: carbon steel, martensitic steel and dual phase steel, are investigated with a variety of electrochemical and surface analytical techniques to understand the mechanism of galvanic corrosion of dual phase steel. The corrosion potential of each steel grade is determined with potentiodynamic technique when the steel is exposed to sodium chloride (NaCl) solution. The study shows that the corrosion potential of dual phase steel is an intermediate between martensitic and carbon steels. In a galvanic coupling of carbon steel/ martensitic steel, carbon steel is found to corrode to protect martensitic steel when exposed to NaCl solution. Examination of dual phase steel after immersion in NaCL solution for an extended period of time indicates the occurrence of galvanic corrosion in the dual phase steel. The corrosion is found to occur primarily in the ferrite phase of dual phase steel.