This study was commissioned by the Learned Society of Wales to better understand, promote and communicate the contribution that Welsh Higher Education Institutions (HEIs) make to wider society. In doing so it takes all 280 publicly available impact case studies (ICS) submitted by Welsh HEIs to the 2021 Research Excellence Framework (REF 2021) and – through complementary quantitative and qualitative approaches – explores the nature of the impacts produced, the mechanisms supporting this and the groups of people that benefit. The case studies present a compelling and inspirational picture of the contributions made by Welsh HEIs beyond academia and Wales’s borders.