A growing body of evidence demonstrates that commercial entities play an important role in shaping the prevalence, incidence, and distribution of obesity. This narrative review examines policy solutions to address the commercial determinants of obesity. We describe how five business sectors (food, beverages, and agriculture; media and entertainment; sports and recreation; transportation; and medical care and pharmaceuticals) shape obesity prevalence through three key behavioral pathways: diet, physical activity, and use of medical care. We then examine four categories of tools available to national and subnational governments to address the commercial determinants: legal and regulatory measures, fiscal policies, market governance mechanisms, and litigation. Finally, we discuss three strategies that can support the successful implementation of these measures: building cross-sectoral support, limiting undue influence in policymaking processes, and designing policies informed by precedent and designed to withstand challenges. We conclude by highlighting key insights for policymakers seeking to make measurable progress in preventing and reducing obesity.