Nanoscale gold–titania (Au/TiO₂) catalysts may provide the right combination of electronic structure, structural dynamics, and stability to facilitate wide ranging chemical transformations, including reactions for utilization of renewable energy sources. The Au/TiO₂-based systems have also emerged as promising photocatalysts capable of promoting light-induced production of hydrogen and other renewable hydrocarbon-based fuels. This Perspective summarizes some of the fundamental aspects and concepts built over the last 30 years that help explain the catalytic and photocatalytic performance of Au/TiO₂ materials. The application of emerging operando methods, based on synchrotron experimental techniques, is also briefly highlighted within the context of key catalytic reactions that may have fundamental importance in renewable energy production and storage.