Metal nanoclusters (NCs) composed of metal atoms and ligands show promise as electrochemiluminescent (ECL) materials due to their optical and electrochemical properties. This review provides a comprehensive overview of the ECL mechanisms, advantages, and roles of metal NCs as luminophores, catalysts, quenchers, substrates, and carriers. Insights into factors that influence ECL in metal NCs will lay the foundation for future research. In addition, the applications of metallic NC-based ECL detection platforms are summarized, and potential research directions of ECL of metal NCs are presented.