Naturally occurring coumarin compounds with the typical benzopyrone framework are found in remarkable concentrations in plants. Moreover, they have also been found in animals, microbes, and other sources. The versatility of the coumarin scaffold extends beyond medicinal chemistry, with applications in agrochemistry, cosmetics, and fragrances. However, this review focuses on the diverse biological activities of metal-complexed coumarin derivatives, including their roles as antimicrobial, anticancer, antioxidant, antidiabetic, anticholinesterase, and antipancreatic cholesterol esterase agents. Notably, the antimicrobial and anticancer properties of these complexes have received significant attention in current research, demonstrating the most promising and impactful results. Coumarin-containing metal complexes have been widely studied in recent years as a growing area of medicinal chemistry in pharmaceutical science. Hence, there is a wide range of potential research topics due to the modifying ability of various ligands, such as N-heterocyclic coumarins, being developed into a metal complex. This has been an innovative strategy in recent years. Therefore, this review article aims to have a concise account and a detailed highlight of the individually associated schematic strategies used in synthesis (carried out through conventional, synthetic, microwave-assisted, and green approaches), along with the characterization of the compounds pertaining with the significant biological activities, which are assessed by suitable evaluating methods.