Although it is seen by many as a form of leisure and recreation, gambling can have serious repercussions for individuals, families, and society as a whole. The harmful effects of gambling have been studied for decades in an attempt to understand individual differences in gambling engagement and the life-course of gambling-related problems. In this publication, we present a comprehensive, internationally relevant conceptual framework of “harmful gambling” that moves beyond a symptoms-based view of harm and addresses a broad set of factors related to population risk, community and societal effects. Interactive factors depicted in the framework represent major themes in gambling that range from specific (gambling environment, exposure, types, and resources) to general (cultural, social, psychological, and biological). The framework has been created by international interdisciplinary experts and stakeholders—including researchers, treatment providers, operators, policy makers, as well as individuals and their families—in order to facilitate an understanding of harmful gambling. It reflects the state of knowledge related to factors influencing harmful gambling; and serves a secondary purpose as a guide for the development of future research programs and education of policy makers on issues related to harmful gambling. Gambling Research Exchange Ontario (GREO) (formerly the Ontario Problem Gambling Research Centre (OPGRC) located in Guelph, Ontario, Canada) has facilitated the development of the Conceptual Framework of Harmful Gambling and will retain responsibility for keeping it up-to-date.