Risk assessment is the management approach or framework of choice in many disciplines, including health care and research, engineering design, and particularly the insurance sector which relies on the best available forward projections of natural hazards and accidents. The marine management community, which includes researchers, practitioners, and resource managers responsible for individual targeted stocks, aquaculture activities, and the marine environment in general, has been slower to take up quantitative risk assessment approaches. Whilst there are prominent examples where risk assessment and management approaches have been applied, they are relatively few. This article theme set presents examples of such and identifies tools and approaches that can be applied to coastal and oceanic marine systems worldwide. The methods developed and the lessons learned from these studies can be used to guide researchers, practitioners, and resource managers. It is hoped that this article theme set will provide an overview of the current state of risk assessment as applied to marine resource management, and stimulate new thinking on how risk assessment approaches can be applied.