This introductory chapter presents the goal of social justice for children and young people to ensure that children are served and protected within their countries and communities. Despite this important goal, children and young people are often overlooked as critical social justice stakeholders with adults and other country experiences prioritized instead. When social justice issues among young people are addressed, it is often through specific interventions rather than taking a comprehensive approach to social justice for children on a macro level. The chapter discusses the importance of children and young people’s involvement as critical stakeholders in systemic social justice reform. Prior models of social justice are critiqued and a call for a contemporary, global approach to social justice for children and young people is warranted. The chapter introduces the parameters of the volume that follows and how it takes an international approach that includes the presentation of case studies from low- and lower-middle-income countries, as well as upper-middle- and high-income countries as per the World Bank’s 2018–2019 new country classifications.