Food systems are central to global sustainability, while being complex systems where places and people are intertwined over large distances and at different scales. Transformations towards sustainable food systems have been called for in both research and policy, and Sweden and the European Union have declared high ambitions to act as global leaders in these transformations. While food production in Sweden and the European Union is often portrayed as largely sustainable in a global context, the region is highly dependent on food imports, with relatively large environmental footprints globally.This thesis aims to explore transformative pathways towards sustainability, with a particular focus on sustainable food systems, in a Swedish and European Union context. The thesis specifically studies the following research questions: (1) What constitutes transformations towards sustainability, and in particular sustainable food systems, from the perspectives of Swedish stakeholders, including food system practitioners, and European Union policy frameworks? (2) What roles, responsibilities, and agency do Swedish stakeholders, including food system practitioners and European Union policy frameworks, attribute to different actors? (3) How can interconnections and accountability in global food systems be understood and governed in light of societal transformations towards sustainability? (4) What are the implications for transformative pathways towards sustainability?The thesis builds on four papers that use focus group methodology (PI and PII), involving Swedish stakeholders, including food-system practitioners, analyses of European Green Deal policies (PII and PIII), and quantitative investigation of phosphorus fertiliser use in Brazilian soybean production and related biodiversity impacts (PIV).Four overarching conclusions are drawn from the findings: (I) Shared goals and consensus are emphasised as essential, while a diversity of transformative pathways and understandings of challenges and priorities needs to be recognised, with attention being paid to how specific choices might include and exclude pathways and actors. (II) Emerging shifts in how food is valued open up opportunities for transformative change in which the 'true' cost of food is acknowledged, alongside a recognition of non-economic values of food, which presupposes alignment at the practical, political, and personal levels. (III) The identified pathways comprise public accountability regimes, incentives for more sustainable consumption, regulations to reduce resource use and impacts of food production. (IV) The attribution of accountability to trading operators in the accountability regime proposed by the European Union highlights an extended focus from food production and consumption towards regulating flows and intermediate actors in food systems.