DC electrodeposition of iron-rich terbium alloys on copper electrodes has been achieved using aqueous citrate solutions. Experiments were carried out in a Hull cell to examine the influence of a wide current density range on the composition and thickness of Fe-Tb alloys. Bright, gray, thin Fe-Tb alloy films were obtained with low current efficiencies. Energy dispersive spectroscopic analysis indicated that Na, S, and O impurities were incorporated in the film. The experimental results demonstrated, for the first time, that Fe promoted terbium electrodeposition. Thus, the alloy codeposition mechanism was classified as the induced type.