The article provides an overview of recent developments in single-entity electrochemistry (SEE), a field that studies electrochemical processes involving individual nanoparticles, proteins, or cells. The review highlights the use of nanoelectrodes, which are electrochemical probes with dimensions in the nanometer range, for various applications such as nucleation and growth studies of nanoparticles, tandem catalysis, and structural evolution. It also discusses the challenges and advancements in sample preparation and immobilization techniques, particularly for single-nanoparticle measurements. The article further explores single-cell electroanalysis, including the use of nanopipette-based configurations for monitoring cellular dynamics and intracellular electrochemical measurements. Additionally, it covers stochastic particle collision experiments, where the interaction of micro/nanoscale entities with ultramicroelectrodes (UME) is studied, and the application of these techniques in biological systems. The review also delves into the use of optical microscopy techniques, such as dark-field microscopy and hyperspectral imaging, to monitor structural and compositional changes in single entities during electrochemical processes. Finally, it discusses the integration of SEE with other electrochemical scanning probe microscopy techniques, such as scanning electrochemical microscopy (SECM) and scanning tunneling microscopy (STM), to enhance the understanding of electrochemical activity at the single-entity level.The article provides an overview of recent developments in single-entity electrochemistry (SEE), a field that studies electrochemical processes involving individual nanoparticles, proteins, or cells. The review highlights the use of nanoelectrodes, which are electrochemical probes with dimensions in the nanometer range, for various applications such as nucleation and growth studies of nanoparticles, tandem catalysis, and structural evolution. It also discusses the challenges and advancements in sample preparation and immobilization techniques, particularly for single-nanoparticle measurements. The article further explores single-cell electroanalysis, including the use of nanopipette-based configurations for monitoring cellular dynamics and intracellular electrochemical measurements. Additionally, it covers stochastic particle collision experiments, where the interaction of micro/nanoscale entities with ultramicroelectrodes (UME) is studied, and the application of these techniques in biological systems. The review also delves into the use of optical microscopy techniques, such as dark-field microscopy and hyperspectral imaging, to monitor structural and compositional changes in single entities during electrochemical processes. Finally, it discusses the integration of SEE with other electrochemical scanning probe microscopy techniques, such as scanning electrochemical microscopy (SECM) and scanning tunneling microscopy (STM), to enhance the understanding of electrochemical activity at the single-entity level.