Marine litter, especially plastics, poses a significant threat to coastal and marine ecosystems, biodiversity, and the social and economic value of coastal areas. Beach clean-ups are a practical, visible, and inclusive citizen science action that mobilisescommunities to remove litter while documenting the impact of their effort. This protocol provides step-by-step guidance for planning and implementing a safe and effective Beach Litter Clean-Up within the REMEDIES project. Citizens play a key role by participating in the clean-up, separating collected materials, and documenting results (e.g., participants, weights, photos) using the REMEDIES Citizen Science tools. The activity supports REMEDIES objectives by raising awareness, enabling structured citizen engagement, and contributing to local actions that reduce plastic pollution and advance the Mission Restore Our Ocean and Waters targets.