Gold(I)-catalyzed activation of alkynes for the construction of molecular complexity has become a powerful tool in organic synthesis. This review highlights the reactivity of alkyne-gold(I) complexes, their ability to activate alkynes for nucleophilic addition, and their role in various transformations, including cycloisomerizations, hydroarylations, and oxidative reactions. Gold(I) complexes are particularly effective in activating π-bonds of alkynes, which is attributed to relativistic effects. These complexes can be used to form a wide range of carbon–carbon or carbon–heteroatom bonds, and their reactivity can be modulated by the choice of ligands. The review discusses the addition of heteronucleophiles (O- and N-nucleophiles) to alkynes, including inter- and intramolecular additions, and their applications in total synthesis. It also covers the reactions of gold(I) complexes with alkenes and alkynes, such as cycloisomerizations of enynes, which proceed through various mechanisms involving the formation of cyclopropyl gold carbenes. Additionally, the review highlights the use of gold(I) in the synthesis of complex molecules, including the formation of spiroketals, bicyclic acetals, and other heterocycles. The review also discusses the role of gold(I) in the hydroarylation and hydroheteroarylation of alkynes, as well as in oxidative reactions. These reactions are often used in the synthesis of natural products and other complex molecules. The review emphasizes the importance of gold(I) catalysts in enabling the efficient and selective formation of complex molecular structures under mild conditions. Overall, the review provides a comprehensive overview of the current state of gold(I)-catalyzed reactions involving alkynes and their applications in organic synthesis.Gold(I)-catalyzed activation of alkynes for the construction of molecular complexity has become a powerful tool in organic synthesis. This review highlights the reactivity of alkyne-gold(I) complexes, their ability to activate alkynes for nucleophilic addition, and their role in various transformations, including cycloisomerizations, hydroarylations, and oxidative reactions. Gold(I) complexes are particularly effective in activating π-bonds of alkynes, which is attributed to relativistic effects. These complexes can be used to form a wide range of carbon–carbon or carbon–heteroatom bonds, and their reactivity can be modulated by the choice of ligands. The review discusses the addition of heteronucleophiles (O- and N-nucleophiles) to alkynes, including inter- and intramolecular additions, and their applications in total synthesis. It also covers the reactions of gold(I) complexes with alkenes and alkynes, such as cycloisomerizations of enynes, which proceed through various mechanisms involving the formation of cyclopropyl gold carbenes. Additionally, the review highlights the use of gold(I) in the synthesis of complex molecules, including the formation of spiroketals, bicyclic acetals, and other heterocycles. The review also discusses the role of gold(I) in the hydroarylation and hydroheteroarylation of alkynes, as well as in oxidative reactions. These reactions are often used in the synthesis of natural products and other complex molecules. The review emphasizes the importance of gold(I) catalysts in enabling the efficient and selective formation of complex molecular structures under mild conditions. Overall, the review provides a comprehensive overview of the current state of gold(I)-catalyzed reactions involving alkynes and their applications in organic synthesis.