Gambling can negatively impact individuals, families, and communities. Public health interventions to prevent or treat gambling problems often focus on reducing harm caused by gambling. However, there is no consistent definition of gambling-related harm for public health to use. There is also no conceptual framework that captures the diverse types of harm due to gambling. A conceptual framework is a network of linked ideas that help to explain a topic, such as problem gambling. The lack of consistent definition and conceptual framework causes difficulties for public health in addressing gambling-related harm. Thus, the current study proposed a definition and conceptual framework of gambling-related harm. The framework identifies and classifies the diverse types of harm that may be experienced by gamblers, affected others, and the broader community.