The CircEUlar project aims to understand the dynamics and levers for societal transformation towards a net-zero emission circular economy. CircEUlar will develop new modelling approaches for analysing circularity from a systems perspective accounting for: 1) dematerialisation and the transition to a service-based economy to limit material stock growth; 2) lifetime extension of material stocks through repair, maintenance, reuse; 3) waste treatment and material recycling. CircEUlar’s approach will be comprehensive, combining new data and modelling of economy-wide material stocks and flows, greenhouse gas (GHG) emissions, and industrial value chains across interlinked sectors, with deep-dive analysis of mobility and buildings as material-intensive demand sectors. These two focus areas have large material stocks, potential for circular transformation, and strong dependence on both circular consumption and production practices. CircEUlar will also focus on digitalisation as a potential enabler of dematerialisation and supply chain circularity. CircEUlar integrates multiple fields of data, knowledge and expertise including: 1) empirical analysis of firm and consumer propensities towards circular economy measures; 2) industry input on process-level innovations and circular economy business models; 3) modelling analysis of economy-wide material stocks and flows, and policy levers of change towards societal transformation. CircEUlar will integrate new insights on circular economy potentials and impacts into EU and global modelling frameworks for: 1) analysing alternative pathways to net-zero GHG emissions; 2) testing effective policy levers for both circular production and consumption. 3) assessing outcomes for climate, environment, economy and society, in line with European Green Deal objectives.