GREEN TALENT addresses gaps in knowledge, skills and competences in research and innovation (R&I) in 4 Widening Countries, supporting the green transition by contributing to halting biodiversity loss and advancing climate mitigation and adaptation through capacity-building, networking and knowledge exchange in four demonstration hubs. Academic and SME partners in each Widening Country provide expertise, support secondments, establish demonstration hubs, and connect to international R&I. Non-Widening partners catalyse GREEN TALENT by enhancing capacity-building, international cooperation, and joint R&I outcomes. GREEN TALENT develops 5 open-access (OA) training modules on R&I support, covering themes such as grant management, communication, entrepreneurship, and intellectual property rights. Additionally, 5 interdisciplinary OA modules focus on nature-based and integrative solutions that address the biodiversity-climate nexus. A programme of 45 secondments is established, providing R&I talents with hands-on learning through job shadowing, peer mentoring, workshops, and networking events. Personalised career plans and comprehensive reintegration strategies ensure secondees’ professional development, enabling them to apply their newly acquired skills within their home organisations. Ongoing follow-up and assessment guarantee the continued use and refinement of these competencies. The 4 Demonstration Pilots in Widening Countries deliver practical, scalable solutions to climate and biodiversity challenges, acting as collaboration hubs between academic and non-academic sectors. These hubs provide secondees with real-world experience and foster partnerships across sectors. All training materials are openly accessible via the GREEN TALENT Capacity-Building Platform, which also shares case-studies of best practices of cross-sectoral R&I, facilitates knowledge exchange and development, and includes an Exchange Forum furthering interdisciplinary dialogue and peer learning.