Macrocycles occupy a unique segment of chemical space. In the past decade, their chemical diversity expanded significantly, supported by advances in bioinformatics and synthetic methodology, and this structural type has now been successfully tested on most biological target classes. The goal of this article is to put into perspective the current applications, opportunities, and challenges associated with synthetic macrocycles in drug discovery. Historically, macrocyclic drug candidates have originated primarily from natural products and peptides. Macrocycles are defined herein as molecules containing at least one large ring composed of 12 or more atoms; they inherently possess fewer rotatable bonds than acyclic analogues, leading to conformational restriction that potentially imparts higher target binding, selectivity, and improved oral bioavailability, making them especially suited for targets with shallow surfaces. However, macrocyclization is often plagued by low yields and requires high dilution conditions. The article first covers drug discovery aspects of macrocycles by target class (e.g., proteases like renin, NEP, thrombin, HIV protease, HCV NS3 protease, BACE-1) to highlight their medicinal chemistry features. The second part discusses technologies and synthetic approaches useful for macrocycle-based drug discovery. Finally, a perspective on the future of synthetic macrocycles in medicinal chemistry is offered.