Liquid salt innovations can offer significant benefits for improving energy efficiency and reducing the environmental impact of the production of many materials and of processing technologies. Technological advancement relies heavily on a sound understanding of the underlying science of the huge number of liquid salts and their varying properties. This Faraday Discussion aims to bring together scientists and engineers from academia and industry to discuss and debate the state of the art in liquid salts to develop a better understanding of their fundamental properties and how their application can help in addressing some of the most important current global challenges. Topics covered include energy efficiency in process chemistry and engineering, improvements in energy conversion and storage and molten salt based reactors in nuclear energy processes.