This review discusses transition metal-catalyzed decarboxylative coupling reactions as a modern strategy for forming carbon–carbon or carbon–heteroatom bonds from carboxylic acids. These reactions involve the cleavage of C-C bonds to carboxylate groups and the formation of new C-C bonds. Decarboxylative cross-couplings are advantageous alternatives to traditional cross-coupling or addition reactions involving preformed organometallic reagents. Decarboxylative reaction variants are also known for Heck-reactions, direct arylation processes, and carbon-heteroatom bond forming reactions. Carboxylate groups are versatile connection points in carbon framework construction. Carboxylic acids are available at low cost and are easy to store and handle. Recent developments have led to a wealth of catalytic transformations of carboxylic acids, providing access to various valuable product classes. Carboxylic acids can react with metals to form either metal carboxylates or acyl metal species, which can be utilized in catalytic transformations. Carbon monoxide gas can be released from acyl metal intermediates, and carbon dioxide gas from carboxylate complexes, with different organometallic species being formed in each case. Decarboxylative coupling reactions can be divided into five categories based on the position and polarity of the bond formation. The focus of this review is on transition metal-catalyzed decarboxylative cross-coupling reactions that have emerged in the last five years. These reactions are important for organic synthesis and have been used to synthesize various compounds, including biaryls, ketones, azomethines, and azaarenes. The review also discusses oxidative decarboxylative couplings, which involve the use of oxidants to facilitate the coupling process. The review highlights the importance of these reactions in the synthesis of various organic compounds and their potential applications in pharmaceutical and agrochemical industries.This review discusses transition metal-catalyzed decarboxylative coupling reactions as a modern strategy for forming carbon–carbon or carbon–heteroatom bonds from carboxylic acids. These reactions involve the cleavage of C-C bonds to carboxylate groups and the formation of new C-C bonds. Decarboxylative cross-couplings are advantageous alternatives to traditional cross-coupling or addition reactions involving preformed organometallic reagents. Decarboxylative reaction variants are also known for Heck-reactions, direct arylation processes, and carbon-heteroatom bond forming reactions. Carboxylate groups are versatile connection points in carbon framework construction. Carboxylic acids are available at low cost and are easy to store and handle. Recent developments have led to a wealth of catalytic transformations of carboxylic acids, providing access to various valuable product classes. Carboxylic acids can react with metals to form either metal carboxylates or acyl metal species, which can be utilized in catalytic transformations. Carbon monoxide gas can be released from acyl metal intermediates, and carbon dioxide gas from carboxylate complexes, with different organometallic species being formed in each case. Decarboxylative coupling reactions can be divided into five categories based on the position and polarity of the bond formation. The focus of this review is on transition metal-catalyzed decarboxylative cross-coupling reactions that have emerged in the last five years. These reactions are important for organic synthesis and have been used to synthesize various compounds, including biaryls, ketones, azomethines, and azaarenes. The review also discusses oxidative decarboxylative couplings, which involve the use of oxidants to facilitate the coupling process. The review highlights the importance of these reactions in the synthesis of various organic compounds and their potential applications in pharmaceutical and agrochemical industries.