Currently, three-dimensional self-supported metallic structures are attractive for their unique properties of high porosity, low density, excellent conductivity, etc., that promote their wide application in fuel cells. Here, for the first time, we report a facile synthesis of Au@Pt3Pd ternary metallic aerogels with a unique dendritic core-shell structure via a one-pot self-assembly gelation strategy. This strategy is simple and saves time without any concentration or destabilizer steps. The as-prepared Au@Pt3Pd ternary metallic aerogels demonstrated enhanced electrochemical performance toward the oxygen reduction reaction compared to that of commercial Pt/C. The unique dendritic core-shell structures, Pt3Pd alloyed shells, and cross-linked network structures are beneficial for the electrochemical oxygen reduction reaction via the electronic effect, geometric effect, and synergistic effect. This strategy of fabrication of metallic hydrogels and aerogels as well as their exceptional properties holds great promise in a variety of applications. [ABSTRACT FROM AUTHOR]