In an effort to improve health and business outcomes, workplaces are supplementing traditional physical activity programs focused on individual behavior change with policies designed to change workplace culture. However, confusion exists about how to define workplace policies. In practice, worksites implement programs, benefit designs, and environmental strategies and describe these as policies. The purpose of this essay is to provide a definition for worksite policy and discuss how policy approaches can support employers’ efforts to promote physical activity. We also describe worksite physical activity policies that employers can adopt and implement.