Administrative data has become a cornerstone for doing research that can inform health promotion, policy, and practice. This chapter explores the role of administrative data in driving evidence-based health decisions, shaping policies, and improving public health outcomes. By leveraging administrative data, relevant stakeholders can identify trends, target interventions, evaluate program effectiveness, and address health and social disparities. The chapter begins with an overview of what constitutes administrative data, highlighting its strengths, limitations, and the sources from which it is derived. It then discusses the practical applications of administrative data in health promotion. The discussion extends to health policy and practice, where administrative data research can play an important role in policy development, resource allocation, and promoting health equity. Through a series of case examples, it provides real-world examples of how administrative data has been effectively used to drive impactful health research. Finally, the chapter discusses global divide in the use of administrative data as well as the future of administrative data research, outlining both the challenges and opportunities that lie ahead.