Oceans and seas have always played a significant role, economically, culturally, and socially, in the development of the Nordic countries. As the global ocean economy is rapidly expanding, the importance of ocean ecosystems and the sustainable use of oceans is an increasing global concern. The Nordic countries have set a vision that the Nordic region will become “the most sustainable and integrated region in the world” by 2030. To make this vision reality, actions for strengthening the sustainability of oceans and ocean industries are called for.This background study was conducted in support of a forthcoming Nordic initiative on Sustainable Ocean Economy with the aim to strengthen Nordic ocean industries by promoting cross-border collaboration, and by creating new opportunities for growth and innovation in the region.By mapping the global context of the sustainable ocean economy, as well as the state and development of the ocean industries in each Nordic country, the mapping seeks to identify Nordic strongholds and cooperation potential that can help existing innovation ecosystems harness new sustainable opportunities.Borrowing the transformation framework used by the High Level Panel for a Sustainable Ocean Economy, the mapping identifies Nordic strongholds across the sectors of ocean food, ocean transport, ocean energy, ocean tourism, seabed mining, and new ocean industries. Nordic strongholds refer to innovation and business areas within the ocean economy where synergies between the countries can be found that create potential for Nordic added value, where the Nordic countries have the potential to be at the international forefront, and where good opportunities exist for upscaling and extended collaboration with leading global initiatives.The mapping identifies interesting innovation and business opportunities related especially to new developments across the sectors of ocean food, ocean transport, and ocean energy. Cross-cutting opportunities, where the Nordic countries are particularly strong, is found in new applications for technology and know-how, improved use of ocean data and digitalisation, and the access to testbeds across the Nordic region.Cooperation opportunities in ocean food, more precisely sustainable aquaculture, is found in developing new protein sources, new products and applications, and the increased use of technology, data, and digitalisation. In ocean transport, opportunities for cooperation relates especially to electrified and autonomous transport systems. Within ocean energy, opportunities is found in advanced and combined offshore energy solutions, distant monitoring and maintenance of offshore sites, and in exploring new ways to develop co-located, sustainable use of ocean areas for multiple purposes.Recommendations for the further scoping of the initiative include considering where most added value can be achieved in relation to other ongoing developments, and to maximise the impact of Nordic cooperation in dialogue with national and global initiatives on the identified themes.