Synthesizing metallic nanostructures with control over morphology, surface chemistry, and length-scale is important for a wide range of applications. Nanostructures having large surface area paired with suitable chemistry are particularly desirable in catalytic applications to facilitate the reaction kinetics. However, the techniques used for nanostructure synthesis are often lengthy, difficult, require expensive precursors/stabilizers, and limit the control over nanostructure morphology/chemistry. Here tuning metallic-glass nanostructures to a wide range of morphologies, where the surface is enriched with catalytic noble metal, is reported. By combining thermoplastic nanofabrication together with electrochemical processing, hierarchical metallic nanostructures with large electrochemical surface area and high catalytic activity are synthesized. Due to the versatility in processing and independent control over multiple length-scales, the approach may serve as a tool-box for fabricating complex hierarchical nanostructures for wide ranging applications.