Environmental challenges pose an imminent threat to people's future and wellbeing. In an effort to tackle climate change and environmental pollution, the European Union has undertaken various steps toward the green transformation of its economic system, the circular transition being an integral part of the process. However, countries still struggle to evaluate the circular economy properly due to the abundance of relevant indicators and monitoring frameworks. This study aims to single out the metrics that are best aligned with the concept of a circular economy, sort through their main determinants and derive common transition models within the European Union context. The results indicate that the recycling rate and the circular material use rate are frequently used to measure material circularity, while the renewable energy consumption is most suited to represent the energy aspect. Considering their common determinants, such as economic development, research and development and resource productivity, a clustering analysis reveals the presence of four distinct groups: countries facing challenges, leaders, energy–efficient representatives and resource–efficient representatives. Investigating the strengths and weaknesses of these transition models can help stakeholders adopt the best practices, address shortcomings and foster innovative solutions to achieve long–term material and energy sustainability.