This review highlights the recent advances and opportunities in transition metal-catalyzed transformations involving dienes, emphasizing their versatility and the emergence of novel reactivity patterns. Dienes, due to their abundance, ease of synthesis, and unique stereochemical properties, are valuable substrates in synthetic chemistry, particularly for the construction of complex, bioactive molecules. The review covers various methodologies for the functionalization of dienes, including hydroalkylation, hydroalkoxylation, hydroamination, and hydroboration, each with detailed examples and mechanisms. Additionally, it discusses difunctionalization reactions such as silylation, carbonylation, carboxylation, and amination, as well as heteroannulation and cycloaddition reactions. These methods offer efficient and atom-economical approaches to creating functionalized compounds, making dienes a crucial component in the synthesis of pharmaceuticals, agrochemicals, and advanced materials. The review also explores the challenges and limitations of these transformations, providing insights into the design of more efficient and selective catalytic systems.This review highlights the recent advances and opportunities in transition metal-catalyzed transformations involving dienes, emphasizing their versatility and the emergence of novel reactivity patterns. Dienes, due to their abundance, ease of synthesis, and unique stereochemical properties, are valuable substrates in synthetic chemistry, particularly for the construction of complex, bioactive molecules. The review covers various methodologies for the functionalization of dienes, including hydroalkylation, hydroalkoxylation, hydroamination, and hydroboration, each with detailed examples and mechanisms. Additionally, it discusses difunctionalization reactions such as silylation, carbonylation, carboxylation, and amination, as well as heteroannulation and cycloaddition reactions. These methods offer efficient and atom-economical approaches to creating functionalized compounds, making dienes a crucial component in the synthesis of pharmaceuticals, agrochemicals, and advanced materials. The review also explores the challenges and limitations of these transformations, providing insights into the design of more efficient and selective catalytic systems.