The circular economy (CE) represents a major paradigm shift of moving from the concepts of linear to circular supply chains across multiple industries. Although some aspects of CE adoption within industrial supply chains have been researched extensively (particularly addressing challenges of design, implementation, and operations), the research that relates CE practices with sustainability performance to reveal the current state of CE practices within small and medium‐sized enterprises (SMEs) is scant. The aim of this research was to facilitate SMEs to achieve greater sustainability through CE implementation. This research addresses three research questions—How are CE fields of action related to sustainability performance? What are the issues, challenges, and opportunities of adopting CE in SMEs? And what key strategies, resources, and competences facilitate effective implementation of CE in SMEs? This study adopts a mixed method approach (qualitative and quantitative) using survey research, focus group, and case studies; 130 randomly selected SMEs within the Midlands of the United Kingdom have been surveyed, and the responses are analysed using statistical tools along with findings from focus groups and case studies. The study reveals that all CE fields of action (take, make, distribute, use, and recover) of SMEs are correlated to economic performance, but only make and use are related to environmental and social performance. The study further derives strategies, resources, and competences for achieving sustainability across all the CE field of actions. Additionally, this research reveals the issues and challenges, strategies, resources, and competences required for implementing CE in SMEs.