While cathodic corrosion may appear as an undesired degradation process at electrode surfaces, it has become a powerful electrochemical method for fabricating nanoparticles and single-atom catalysts. In contrast to traditional wet chemical synthesis, cathodic corrosion affords rapid, straightforward, capping-agent-free production of nanoparticles, enabling fine control over size, shape, and elemental composition. This mini-review summarizes recent advances in cathodic corrosion-based synthesis, emphasizing its unique capabilities for producing metallic, alloyed, and oxide nanoparticles, as well as single-atom catalysts. It explores the effects of varying parameters such as electrode material, electrolyte composition, voltage waveform, and frequency on the characteristics of the generated particles. Furthermore, it highlights the enhanced electrocatalytic or photoelectrocatalytic performance of the nanoparticles produced via cathodic corrosion.