UN Environment Programme and the Open University have created a Massive Open Online Course (MOOC) on Marine Litter. It is part of Clean Seas and contributes to the goals of the Global Partnership on Marine Litter. This MOOC presents various options and tools to combat marine pollution such as the use of tools like the Honolulu Strategy. The course provides case studies to inspire leadership and stimulate creative solutions to marine litter problems. This course benefits policymakers, practitioners, and managers who wish to connect with other professionals to enhance their knowledge of marine litter issues.