In this article for the 40th Anniversary of the Journal of Public Policy & Marketing, the authors first share what is meant by “policy,” “public policy,” and “marketing and public policy” for researchers in our field. The authors then offer examples of JPPM research informing policy and related communities interested in critical societal issues for public health and consumer well-being across stages of the policy-making process: problem identification, agenda setting, policy formulation, budgeting, implementation, and evaluation. The authors also discuss important sources of public policy (e.g., federal, state, and international agencies; self-regulation; the courts; nonprofits; society; industry standards; company policies; personal ethics) and their role in the marketing and public policy process. The authors then offer JPPM application examples (consumer protection; antitrust/competition; vulnerability; diversity, equity, and inclusion; nutrition labeling; addiction, cannabis, and antidrug research; tobacco warning labeling and education; and privacy and technology) and share ideas for developing research that contributes to the marketing and public policy discipline and in making a positive difference in society and people’s lives.