The EU Mission ‘Restore our Ocean and Waters’ (Mission Ocean) aims at protecting and restoring the health of our ocean and waters through research and innovation, citizen engagement, and blue investments by 2030. The creation of the European Digital Twin Ocean (EU DTO) supports this mission as well as the key initiative of the European Commission, Destination Earth (DestinE), aiming at developing a highly accurate digital model of the Earth on a global scale to be able to monitor, simulate, and predict the interaction between natural phenomena and human activities. Addressing the Horizon Europe call HORIZON-MISS-2023-OCEAN-01-8, SEADITO focuses on the need for a targeted set of analytical methods and tools to support the development of the EU DTO including integrating social-ecological models in order to establish a comprehensive decision support platform. SEADITO aims at increasing transdisciplinary abilities of social-ecological models by updating and integrating them for improved Ecosystem-based Management, and a set of case studies in the Baltic Sea, the North Sea and the Mediterranean as well a Pan- European case study will provide the contexts for the multi-actor processes identifying user needs, as well as co-designing and testing components and services in the targeted user communities. The results will include sets of interoperable, spatial explicit, and DTO compliant social-ecological decision-support components based on FAIR principles (e.g. to be integrated with EDITO-Model Lab), as well as scalable and multi-level social-ecological models, integrated quantitative and qualitative social-ecological indicators, and workflows quantifying and integrating cultural and behavioural aspects. The components will be tested through an interactive spatial platform, the SEADITO Explorer equipped with visual demonstrators of social-ecological models and a Scenario Toolkit (WIST). Learning materials will target young researchers, decision-makers, and the public.