Although legal interventions are responsible for many sentinel public health achievements, law is underutilized as a tool for advancing population health. Our purpose was to identify critical opportunities for public health lawmaking. We articulated key criteria and illustrated their use with 5 examples. These opportunities involve significant health problems that are potentially amenable to change through law and for which an effective legal intervention is available: optimizing graduated driver licensing laws, increasing tax rates on alcoholic beverages, regulating sodium in foods, enacting laws to facilitate reversal of opioid overdoses, and improving mental health interventions in the college setting. We call for a national conversation about critical opportunities for public health law to advance evidence-based policymaking.