Public health policy has a profound impact on health status. Missing from the literature is a clear articulation of the definition of evidence-based policy and approaches to move the field forward. Policy-relevant evidence includes both quantitative (e.g., epidemiological) and qualitative information (e.g., narrative accounts). We describe 3 key domains of evidence-based policy: (1) process, to understand approaches to enhance the likelihood of policy adoption; (2) content, to identify specific policy elements that are likely to be effective; and (3) outcomes, to document the potential impact of policy. Actions to further evidence-based policy include preparing and communicating data more effectively, using existing analytic tools more effectively, conducting policy surveillance, and tracking outcomes with different types of evidence.