The third edition of Introduction to Public Health has been extensively revised and updated to reflect the impact of the COVID-19 pandemic and the need to recalibrate how public health is organized, financed, and planned in the 21st century. Written by experienced public health practitioners and academics, this foundational resource presents a thorough overview of the US public health system from its origins to current state and future directions, and examines the new outlook for students seeking careers in this dynamic and exciting field. The textbook offers a sweeping examination of topics such as infectious disease control, injury prevention and noninfectious diseases, system performance and improvement, and public health leadership and communication. Emphasis is placed on efficiency, effectiveness, and equity for public health leaders to garner public support for evidence-based programs and develop a stronger, well-financed public health infrastructure to achieve population health improvements. An engaging narrative that is richly illustrated, Introduction to Public Health will challenge and inspire the next generation of public health leaders and practitioners to tackle the complex issues facing us today.