Compared with general additive manufacturing (AM) methods, Multi-material additive manufacturing (MMAM) enables a higher level of design freedom, such as integrating materials, structure and function to achieve tailorable functionalities (e.g., local wear resistance, high thermal conductivity, thermal insulation, and chemical corrosion resistance, etc.). However, MMAM of metallic materials is a recent research activity still in its embryonic stage. Notably, there has been so far no comprehensive review about metallic MMAM covering both macroscale fabrication to microscale fabrication.