The effect of cerium ion on the formation, morphology, composition, and corrosion behavior of Ni–cerium oxide coatings was investigated by SEM, FESEM, XRD, EDS, XPS, EIS, and potentiodynamic polarization. The extremely highest corrosion resistant coating was obtained when the cerium ion concentration in the plating bath was 16 mM. It has been observed that the presence of cerium ion in the plating bath led to changes in the morphology of the coating from pyramid nodular structure to coaxial structure. By adding cerium ion to the plating bath, a considerable grain refinement in the nanometer region was observed.