Biocompatible nanocarriers hold significant potential as versatile systems for delivering photosensitizers (PSs) in therapeutical applications. Their ability to address solubility and stability issues of lipophilic PSs, carry combinations of PSs and other therapeutic agents to a target site, and improve biodistribution following intravenous injection while reducing side effects make them an attractive option for advancing photodynamic therapy (PDT) across various applications. To achieve these potential benefits as a viable therapeutic option, the design and optimization of nanocarriers, including material selection and comprehensive photochemical and technological characterization, are crucial. This presentation will provide a brief overview of the critical steps in designing nanocarriers for PS delivery and then show examples of nanocarriers tailored for combining PDT and chemotherapy and treating bacterial infections. Additionally, the integration of nanocarriers in macroscale platforms such as hydrogels will be discussed as a strategy for the local delivery of PSs.