7 pages, 4 figures.-- Data availability: No data was used for the research described in the article The world is struggling to limit greenhouse gas emissions and reduce the human footprint on nature. We therefore urgently need to think about how to achieve more with actions to address mounting challenges for human health and wellbeing from biodiversity loss, climate change effects, and unsustainable economic and social development. Nature-based Solutions (NBS) have emerged as a systemic approach and an important component of the response to these challenges. In marine and coastal spaces, NBS can contribute to improved environmental health, climate change mitigation and adaptation, and a more sustainable blue economy, if implemented to a high standard. However, NBS have been largely studied for terrestrial – particularly urban – systems, with limited uptake thus far in marine and coastal areas, despite an abundance of opportunities. Here, we provide explanations for this lag and propose the following three research priorities to advance marine and coastal NBS: (1) Improve understanding of marine and coastal biodiversity-ecosystem services relationships to support NBS better designed for rebuilding system resilience and achieving desired ecological outcomes under climate change; (2) Provide scientific guidance on how and where to implement marine and coastal NBS and better coordinate strategies and projects to facilitate their design, effectiveness, and value through innovative synergistic actions; (3) Develop ways to enhance marine and coastal NBS communication, collaboration, ocean literacy and stewardship to raise awareness, co-create solutions with stakeholders, boost public and policy buy-in, and potentially drive a more sustained investment. Research effort in these three areas will help practitioners, policy-makers and society embrace NBS for managing marine and coastal ecosystems for tangible benefits to people and marine life The study received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement MaCoBioS (contract no 869710), FutureMARES (contract no 869300) and REST-COAST (contract no 101037097) With the institutional support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S) Peer reviewed