Ocean literacy is defined as understanding of human influence on the ocean and the ocean influence on humans. Ocean literacy is not only about increasing awareness on the state of the ocean, but it is about providing tools and approaches to transform ocean knowledge into actions to promote ocean sustainability. Ocean Literacy as concept and approach is radically evolving from being a tool to be applied in formal education and training contexts to a tool and an approach for society as a whole, aimed at triggering actions towards ocean sustainability. The UN General Assembly declared 2021-2030 the Decade of Ocean Science for Sustainable Development, and the IOC of UNESCO has been tasked to coordinate its preparatory phase. In this context, Ocean Literacy is expected to play an important role.