Achieving sustainable ocean economies has become a global priority. The ocean is at the centre of the livelihoods of more than 3 billion people worldwide, and it is a key life-support system for all life on this planet. However, pressures on the ocean and the ecosystem services it provides have mounted significantly — from overfishing, pollution, and climate change — and are expected to further grow as the ocean becomes the stage for a range of new ocean-related economic activities. These pressures are pushing the health of the ocean to its limits, leading to habitat degradation, ocean warming and acidification, more frequent extreme weather events, and species extinctions. They undermine the ocean’s ability to support long-term socio-economic benefits and sustainable development. Actions to revert these trends are therefore urgently needed: new and traditional ocean-based economic activities need to use ocean resources sustainably and conserve them. In recognition of this, for the first time the world agreed to focus on the ocean in the 2030 Agenda for Sustainable Development, through a dedicated Sustainable Development Goal (SDG 14) and ocean action has since become a key priority in international fora, including in recent G7 and G20 agendas.