Small and medium enterprises (SMEs) are key actors in the implementation of the circular economy (CE) concept as a basis for creating sustainable societies. Thus, the main objective of this study is to identify key strategies and resources that may favor CE implementation in SMEs. These key strategies should encourage SMEs to develop eco-innovations to gain competitive advantage and create and capture value that is coherent with nature. A mixed-method approach that consisted of a literature review and a focus group for gathering qualitative data was used. This focus group was made up of experts such as researchers and practitioners from universities, sustainable SMEs, and consultancy firms in Spain. A set of strategies and internal and external factors were identified to help SMEs to implement the CE. Finally, some useful dynamic capabilities for implementing the CE in business performance were identified.