Recent data indicate accumulation areas of marine litter in Arctic waters and significant increases on the seafloor over time. Beaches on remote Arctic islands may be sinks for marine litter and reflect pollution levels of the surrounding waters particularly well. We provide the first quantitative data from surveys carried out by citizen scientists, which participated in sailing cruises around Svalbard in 2016. Litter quantities on six beaches varied from 9 - 524 g m-2 and were similar to those from densely populated areas. Plastics accounted for > 80% of the overall litter, most of which originated from fisheries. Photographs provided by citizens show deleterious effects of beach litter on Arctic wildlife including polar bears (Ursus maritimus), which is already under strong pressure from global climate change. Our study highlights the potential of citizen scientists to provide scientifically valuable data on the pollution of sensitive remote ecosystems. Similar programmes could be adopted in other poorly sampled areas of the world to increase our knowledge base and to stimulate a sense of connectedness with the environment visited.