This publication, developed within the Joint Nordic Seaweed Innovation Network (JNSIN), examines the role of species of the green seaweed Ulva in the Nordic green transition. Cultivation provides sustainable biomass for food, feed, and bioproducts while reducing nutrient pollution and capturing carbon. Nordic waters present variable conditions, but Ulva species tolerate fluctuations in temperature, salinity, light, and nutrients, making it suited for marine and land-based systems and potentially integration into multi-use ocean hubs with aquaculture and offshore energy. Addressing challenges such as reproductive control, microbiome interactions, cultivation protocol optimization , and automation will unlock Ulva’s potential to deliver ecosystem services, strengthen coastal resilience and support a circular bioeconomy.