Private food safety standards have become an important governance mechanism in contemporary food supply chains. While much has been written about private standards from the perspectives of different academic fields, there has never been a dedicated literature review to examine their interaction with global food supply chains. In this systematic review, 45 peer reviewed articles on private food standards, selected through extensive searches in four academic databases are critically appraised. Our analysis reveals that the most studied European private food safety standards are owned by retail conglomerates and therefore place the retail sector in a position of influence in the supply chain. These standards influence supply chain structures, market access, and the efficiency of food safety management systems. They also challenge the traditional relationship shared by actors in the supply chain with public authorities and the World Trade Organization. In the recent years, their scope has expanded to include topical issues such as environmental sustainability, worker safety, and animal welfare. Overall, the review suggests that European private food safety standards alter the operations of modern agri-food supply chains to accommodate consumer wishes while allowing the retail sector to exert its influence without taking on additional legal and economic liability.