This report presents the main findings from a socio-economic impact study of Diamond Light Source (“Diamond”), which was undertaken by Technopolis — together with the Diamond team — in 2018-2019 and involved a range of surveys, interviews, case studies and desk-based assessments. The study set out to measure and demonstrate Diamond’s scientific, technological, societal and economic benefits, contributing to the available evidence base and serving as an input to future funding requests. It was also to provide recommendations for future monitoring and evaluation efforts, including for any additional data or methods that would be beneficial.