In this course, we provide an overview of systems thinking and systems models relevant for a public health leader to act efficiently. Public health and health policy-related challenges are complex systems compounded with many stakeholders, institutions and risk factors attached to them. Health outcomes depend on many interdepartmental actors and their transactions. Therefore, the result cannot be predicted with confidence using traditional statistical methods. “Systems Thinking” is a core skill in public health and helps public health leaders to remain aware of and prepare themselves much before for many unintended consequences. In learning systems thinking, a participant gathers knowledge and skills and recognizes the influence of role players and multiple socio-system perspectives. It helps to formulate a framework or model that can depict and predict the unintended outcomes of policy changes in an environment. Systems thinking and systems models are tools for a public health leader to devise strategies for solving real-world complexities. This course has four-course credits having four modules, and each module contains three units, and therefore 12 units. It is designed in such a way so that students get a theoretical understanding of the topic, and from various case analyses, they relate themselves to ground realities.