This review discusses the role of ligand effects in homogeneous gold (Au) catalysis, focusing on how ligands, counterions, and oxidation states influence selectivity in various Au-catalyzed reactions. The review highlights the development of efficient and selective Au-catalyzed transformations over the past decade, emphasizing the importance of ligand design in controlling chemo-, regio-, and stereoselectivity. It also explores the impact of relativistic effects on Au reactivity and provides a comprehensive overview of the progress in Au catalysis, particularly in the areas of asymmetric catalysis, nucleophilic addition to carbon π-electrophiles, and cascade reactions. The review begins with an introduction to the context and scope of Au catalysis, followed by a detailed discussion of ligand effects in various reaction types. It covers the asymmetric catalysis of aldehydes, the activation of carbonyl compounds, and the addition of nucleophiles to carbon π-electrophiles. The review also addresses the use of Au catalysts in polymerization chemistry and the carbonylation of olefins. Key findings include the role of ligands in controlling enantioselectivity, the influence of counterions on reaction outcomes, and the importance of oxidation state in determining catalytic activity. The review highlights the development of new ligands and catalysts that enable high selectivity in various reactions, such as the hydroalkoxylation and hydrocarboxylation of allenes, the hydroamination of allenes, and the cycloisomerization of 1,5-enynes. The review also discusses the challenges in achieving high enantioselectivity and the potential of using chiral counterions in Au catalysis. Overall, the review provides a comprehensive overview of the current state of Au catalysis, emphasizing the importance of ligand design in achieving high selectivity and efficiency in various reactions. It also highlights the ongoing research and development in this field, with a focus on the potential of Au catalysts in future applications.This review discusses the role of ligand effects in homogeneous gold (Au) catalysis, focusing on how ligands, counterions, and oxidation states influence selectivity in various Au-catalyzed reactions. The review highlights the development of efficient and selective Au-catalyzed transformations over the past decade, emphasizing the importance of ligand design in controlling chemo-, regio-, and stereoselectivity. It also explores the impact of relativistic effects on Au reactivity and provides a comprehensive overview of the progress in Au catalysis, particularly in the areas of asymmetric catalysis, nucleophilic addition to carbon π-electrophiles, and cascade reactions. The review begins with an introduction to the context and scope of Au catalysis, followed by a detailed discussion of ligand effects in various reaction types. It covers the asymmetric catalysis of aldehydes, the activation of carbonyl compounds, and the addition of nucleophiles to carbon π-electrophiles. The review also addresses the use of Au catalysts in polymerization chemistry and the carbonylation of olefins. Key findings include the role of ligands in controlling enantioselectivity, the influence of counterions on reaction outcomes, and the importance of oxidation state in determining catalytic activity. The review highlights the development of new ligands and catalysts that enable high selectivity in various reactions, such as the hydroalkoxylation and hydrocarboxylation of allenes, the hydroamination of allenes, and the cycloisomerization of 1,5-enynes. The review also discusses the challenges in achieving high enantioselectivity and the potential of using chiral counterions in Au catalysis. Overall, the review provides a comprehensive overview of the current state of Au catalysis, emphasizing the importance of ligand design in achieving high selectivity and efficiency in various reactions. It also highlights the ongoing research and development in this field, with a focus on the potential of Au catalysts in future applications.