The development of clean sustainable energy technologies has been significantly promoted by advances in electrocatalysts, especially for lowdimensional metallic nanomaterials (LDMNs), which have distinctive structural, physiochemical, and electronic properties, including a highly active surface area, efficient electron transfer, and rich surface unsaturated atoms. Recent advances have also revealed that surface engineering, interface engineering, and strain engineering for LDMNs can readily lead to increased surface active centers, strong synergistic effects, and electronic modulation, thus providing new approaches that greatly promote the electrocatalytic performance. In this review, the recent progress in LDMNs is highlighted in the context of their potential as electrocatalysts with superb performance for advanced electrocatalytic reactions. The latest achievements in their structural design, controllable synthesis, mechanistic understanding, and avenues for performance enhancement are illustrated. Strategies for controlled synthesis of high-quality LDMNs and discussed, and to boost the future development of LDMNs for energy-related conversion technology, future perspectives and potential challenges are also proposed.