Our knowledge of the status and trends in natural resources and the environment in the Arctic is limited, making natural resource management decisions difficult. One challenge is how to reach remote, uninhabited wilderness areas in order to obtain much-needed data and this is where expedition cruises can play a crucial role. Through the collective intelligence of resident communities and visitors, citizen science enables valuable data and information to be generated from local and outside sources of knowledge. This chapter outlines a citizen science pilot program of environmental monitoring by Arctic expedition cruises in Svalbard and Greenland during 2019 conducted to understand the potential this kind of environmental monitoring may have and to identify suitable approaches for enhancing data collection, management, and knowledge sharing. Four citizen science projects were piloted: two biodiversity projects, one environmental and one meteorological project. Biodiversity monitoring and recording through the eBird and Happywhale platforms were by far the most popular projects in the program, reflecting the interests of expedition cruise participants and highlighting the need to consider participant motivation and preferences in the design of such programs. Observations are more likely to be used by decision-makers in the Arctic if records are analyzed and interpreted with a view to informing decision-making processes and if the findings are communicated to decision-makers in appropriate formats. An intermediary organization that can facilitate the dialogue and knowledge transfer between citizen science programs, scientists, and decision-makers is essential to ensuring that data actually enter the decision-making processes. Mobilizing the collective intelligence of visitors, staff, and local communities can make a significant contribution to better environmental decision-making and strengthen efforts to adapt to climate change in the Arctic.