There is a lack of academic attention towards the relationship between local governments and circular economy social innovations. While academic evidence suggests that local governments and policymakers can positively affect the success of social innovations, there is a lack of in-depth studies on how exactly they support social innovation. The main question of this study: How does the municipality of Rotterdam respond to the emergence of social innovation in circular economy, specifically to CCIs? This study aims to discover what circular economy social innovations entails in the municipality of Rotterdam, what policies and policy instruments are employed by the municipality of Rotterdam vis-à-vis circular citizen initiatives, how the interaction between the municipality of Rotterdam and circular citizen initiatives affects the transformative capacity of the latter, which bottlenecks and/or tensions are experienced with regards to the relationship between the municipality and circular citizens initiatives, and how the bottlenecks should be resolved according to circular citizen initiatives and the municipality of Rotterdam. The Local Climate Policy and Action framework, and transformative social innovation theory are utilised to develop semi-structured interviews. Said interviews are conducted among two civil servants who are involved with the citizen initiative, six participants of the citizen initiatives, and two academic experts. The results reveal four main bottlenecks: clashing institutional logics, tensions between civil servant and CCI participants, municipal and national regulations, clashing ideas of value-creation, and provision of accommodation. Analysis also revealed that the municipality does improve the transformative capacity of CCIs, albeit to a limited extent. Subsequently, these results discussed and explain using historic accepted practises that ensue from historic institutional logics. The paper continues by drawing conclusions regarding the discussed results and answering the research questions. Finally, recommendations for future research are made.