Oceans and Human Health (OHH) is an emerging meta-discipline exploring the complex and inextricable links between the health of the ocean and that of humans. This linkage between ocean health and public health emphasises an urgent need for interdisciplinary cooperation between researchers and decision-makers. A participatory and inclusive approach was advocated and adopted by the EU Horizon 2020 project SOPHIE. In 2019, dialogue forums were carried out online and in-person, engaging thousands of expert and citizen stakeholders across Europe, to identify key priorities for protecting public health and the health of the marine environment. These forums used Collective Intelligence, a systems methodology that specialises in facilitating group discussion and consensus building.