The need for sustainability transitions is widely recognised, along with a concurrent need for the evolution of knowledge systems to inform more effective policy action. Although there are many new policy targets relating to net zero emissions and other sustainability challenges, cities, regional and national governments are still struggling to rapidly develop transformational policies to achieve them. In this session we propose to share and extend insights from a previous academic-practitioner collaboration related to our work at the science-policy interface. The collaboration included researchers working directly within government agencies of European Environment Agency (EEA), the UK Department for Environment, Food and Rural Affairs, Natural England, and members of scientific advisory committees for these bodies. Through this collaboration, particularly in the development of the EEA’s landmark document The European environment — state and outlook 2020, we have identified specific knowledge and competency needs for governing sustainability transitions related to the interlinked phases of envisioning, implementing and evaluating. In short, we argue that coordinated reforms of both policy and knowledge systems are urgently needed to address the speed and scale of sustainability challenges. These include embedding systems thinking literacy, mainstreaming participatory policy making, expanding the capacity to undertake transdisciplinary research, more adaptive governance and continuous organisational learning. These processes must guide further knowledge development, uptake and use as part of an iterative and holistic process. Such deep-seated change in policy-knowledge systems will be disruptive and presents challenges for traditional organisational models of knowledge delivery but is essential for successful sustainability transformations.