Sustainable production and consumption of food systems cannot be achieved without considering the entirety of the supply chain and the actors involved at each stage along the way. This requires more in-depth analyses of social dimensions often neglected in favor of the environmental and economic ones. Yet, inattention to the social dimension of sustainability in food supply chains has yielded a lack of agreement regarding what to consider and how to measure it. This review identifies the current state of art of how social sustainability aspects are measured through various tools and indicators, following the “Preferred Reporting Items for Systematic Reviews and Meta-Analyses” (PRISMA) protocol. The selection criteria resulted in 101 papers and gray literature documents published from 2000 to 2021. Thirty-four social sustainability tools are analyzed based on five food supply chain stages, namely production, processing, wholesale, retail, and consumer and four stakeholders as adapted from the most recent Social Life Cycle Assessment guidelines, namely farmers, workers, consumers, and society. Production and processing-related assessment tools are mostly publicly funded, while wholesale, retail, and consumer tools are often privately funded. Moreover, the availability of assessment tools decreases along the supply chain. Production has the highest number of tools (17) and quantitative indicators, targeting mostly farmers through job conditions and quality of life indicators. Processing stage tools (5) target mostly workers, through quantitative indicators related to fair job conditions. The wholesaler stage tools (4) and indicators are the least connected, while the retail stage (2) is the most inclusive in terms of qualitative social sustainability indicators. The consumer stage tools (2) also has a low number of social indicators and interactions, despite being the stage that influences the supply chain the most. It is clear that food supply chain stakeholders can benefit from the implementation of social sustainability aspects, although these benefits become inconsistent if not respected in each stage. A need for an unceasing thread of respected social sustainability should permeate the whole supply chain, as environmental certification currently does, becoming the priority for policy makers in the sector to focus their attention on the emerged hotspots for intervention from this research.