Research on social capital in public health is approaching its 20th anniversary. Over this period, there have been rich and productive debates on the definition, measurement and importance of social capital for public health research and practice. As a result, the concepts and measures characterising social capital and health research have also evolved, often drawing from research in the social, political and behavioural sciences. The multidisciplinary adaptation of social capital-related concepts to study health has made it challenging for researchers to reach consensus on a common theoretical approach. This glossary thus aims to provide a general overview without recommending any particular approach. Based on our knowledge and research on social capital and health, we have selected key concepts and terms that have gained prominence over the last decade and complement an earlier glossary on social capital and health.