Atomically precise gold-based nanoclusters have attracted increasing attention in catalysis owing to their well-defined atomic structures, discretely tunable electronic energy levels, and highly designable surface chemical environments. Serving as an important bridge between molecular complexes and metal nanoparticles, gold nanoclusters exhibit outstanding catalytic activity and selectivity and provide ideal model systems for elucidating structure–property–reactivity relationships at the atomic level. Recent advances in synthetic and characterization techniques have led to remarkable progress in the application of gold nanoclusters in photo- and thermocatalytic reactions encompassing selective oxidation and reduction, C−C and C−heteroatom coupling, multicomponent transformations, and asymmetric catalysis. This review systematically summarizes recent developments in gold nanocluster catalysis across different reaction classes, focusing on the roles of heterometal doping, ligand engineering, and metal–metal cooperative effects in modulating catalytic behavior. Furthermore, fundamental design principles for achieving the desired reaction pathway and selectivity control at the atomic scale are distilled to provide guidance for the rational development of efficient and sustainable catalytic systems.