Public health has never been more important, or more controversial. What states do, and fail to do, makes a significant difference to the lives we are able to lead. Putting public health first would allow improvements to the health of everyone, especially the worst off. Yet many citizens actively oppose state interference to improve population health, complaining that it encroaches on personal liberty. How should policymakers reconcile these conflicting priorities? This groundbreaking book argues that philosophy is not just useful, but vital, for thinking coherently about priorities in health policy and public policy. Novel, theoretically rigorous, yet practical, Philosophy for Public Health and Public Policy examines why it is so common for public policies to fail in practice to improve the problems they aim to solve, and what to do about this. It argues that a shift to complex systems approaches to policymaking is overdue. Philosophers need to become much more attuned to the contingency and messiness of real-world policymaking, and to the ways in which philosophical tools such as thought experiments are frequently unreliable. The book also provides an ethical framework for public health policy. It argues that public health is a right of citizens, alongside more familiar rights such as liberty and security. Public health should not be thought of merely as interference with the rights that individuals have, but as necessary to protect these rights. Chapters explore implications for resource allocation, personal responsibility, health equity, and the control of communicable disease.