Engaging in policy making is an essential activity of public health agencies and staff to achieve the goals of Public Health 3.0 and to work collaboratively to address the social determinants of health. This training provides an overview of the policy making process as defined by the Centers for Disease Control, draws on the COVID-19 and other complex public health problems to discuss the challenges commonly faced by public health agencies during this policy process, and makes the case for using a systems thinking approach to overcome these policy roadblocks and address unintended consequences.