The social dimension of sustainability in supply chains has grown in importance in both academic and industrial communities. This article aims to understand how social dimension has been incorporated in supply chain management research in the past years and what research gaps still exist. For this purpose, a systematic literature review is performed where 621 articles are analysed considering a set of categories that include: research methodology; social dimension; social analysis focus; supply chain entities; traceability and transparency; uncertainty and risk; industrial activity sector. A cross-analysis between categories is presented, revealing that social sustainability concerns have been increasingly addressed along the years, but further research still needs to be performed to achieve more inclusive social supply chains. N-Vivo Software is used to perform the content analysis. The main research gaps and trends regarding social concerns in supply chains are identified and systematised into a framework that can be used to integrate social aspects in supply chains. Based on the latter, a research agenda is defined targeting concerned researchers and practitioners to attain the sustainable supply chains.