This chapter, “Health in Conflict,” addresses the relationship between international humanitarian law and global health policy in both safeguarding public health and protecting human rights in conflict-affected settings. While the International Committee of the Red Cross (ICRC) has long overseen humanitarian responsibilities under international law, the changing nature of conflict and increasing harms to civilians—from World War II to today—has reframed international humanitarian law obligations to support the rule of law in complex emergencies. This has been achieved through the Geneva Conventions and rising global institutions to address the protection of civilians and other noncombatants in international armed conflict (IACs) and non-international armed conflicts (NIACs). These institutions that apply international humanitarian law provide a path to address major public health challenges in conflict-affected settings, including infectious diseases; non-communicable diseases; mental health and trauma; sexual and reproductive health and violence prevention; and water, sanitation, and hygiene. In conflict-affected settings, health professionals can become either complicit in human rights abuses or subject to human rights violations themselves. Considering past perpetration of human rights abuses and international crimes—including war crimes, crimes against humanity and genocide—by aid professionals, it is critical for global health law to address the threat to health care from attacks against health systems amid complex humanitarian emergencies instigated and exacerbated by armed conflict.