This chapter examines the application of justice theory to three critical public policy domains: health, education, and the environment. Rejecting technocratic compartmentalization, it argues for a holistic, intersectional, and normatively rich account of sectoral justice that integrates distributive, procedural, and recognitional dimensions. Drawing on both philosophical frameworks and empirical studies, it explores how institutional design, democratic accountability, and the politics of indicators shape the ethical terrain of public goods provision. The chapter traces the entanglement of justice with structural inequality, particularly as experienced across gendered, racialized, and postcolonial contexts. It critically interrogates the limits of existing policy metrics and advocates for morally reflexive, ecologically sensitive, and participatory approaches to policy reform. Ultimately, the chapter posits justice not as a corrective to sectoral failures but as a transformative ethos that reimagines governance, legitimacy, and collective responsibility in an increasingly interdependent world.