This chapter provides an understanding of the legal foundations of human rights, examining human rights under international law as a basis for social justice in public health. International human rights law has codified the rights first enumerated in the Universal Declaration of Human Rights (UDHR), evolving through the politics of the Cold War to develop the International Covenant on Economic, Social and Cultural Rights (ICESCR). This seminal covenant and the international treaties that derived from it have framed the legal foundations of the human right to health and the evolution of health-related human rights. Yet, where challenges remain in responding to the health needs of a globalizing world, scholars and advocates have looked to a shift from international health law to global health law, facilitating collaboration between state and nonstate actors in an expanding global health policy landscape.