This study proposes a quantitative multi-criteria framework to measure the social pillar of circular tourism, bridging the analytical gap between environmental resource efficiency and socio-economic equity. By aligning the Global Sustainable Tourism Criteria (GSTC) with the 5R principles (reduce, recycle, repair, rethink and reuse), the Composite Social Circularity Index (CSCI) was constructed using Eurostat NUTS 2 data across 242 European regions over the 2018–2024 horizon. The methodology applies the entropy weighting method to synthesise complex indicators, such as circular workforce training, sharing economy participation and specialised repair employment. The empirical results reveal a significant circular divide within the EU-27. While a prominent northern-Alpine corridor excels in high-tech rethink strategies, peripheral regions remain caught in structural linear traps. However, a unique social repair buffer was identified in the Mediterranean region, where traditional SME-led repair cultures provide organic labour market resilience. The paper provides a standardised tool for policymakers to monitor the just transition, advocating for social conditionality parameters to ensure that circularity benefits both the environment and the regional labour force.