Carbon quantum dots and their incorporation in various polymer matrices are reviewed. In general, the importance of such polymer nanocomposites in biomedical applications is highlighted. In particular, the physical and antimicrobial properties of carbon quantum dots and their ability to produce reactive oxygen species under certain conditions using the principle of photodynamic therapy are explored. The characterization, preparation, mechanism of action, and use of carbon quantum dots are discussed. The known combinations of polymers and carbon quantum dots and their use in various industries are also described. Carbon quantum dots and their incorporation in various polymers, especially in biomedical applications, are evaluated. The characterization, preparation, mechanism of action, and use of carbon quantum dots are discussed. Additionally, the known combinations of polymers and carbon quantum dots and their use in various industries are described.