The public health literature has not fully explored the complexities of the policy process as they relate to public health practice and obesity prevention. We conducted a review of the literature across the policy science and public health fields, distilled key theories of policy making, and developed a framework to inform policy, systems, and environmental change efforts on obesity prevention. Beginning with a conceptual description, we focus on understanding three domains of the policy process: the problem domain, the policy domain, and the political domain. We identify key activities in the policy process including the following: (a) assessing the social and political environment; (b) engaging, educating and collaborating with key individuals and groups; (c) identifying and framing the problem; (d) utilizing available evidence; (e) identifying policy solutions; and (f) building public support and political will. The article provides policy change resources and case studies to guide and support local and state efforts around obesity prevention.