Global sustainability assessments call for a rethinking of prevailing systems of production and consumption. We focus on the circular economy as an alternative system, and the role of cooperatives as transformative actors for sustainability. While cooperatives have been studied in relation to specific circularity strategies, notably recycling, we present the first study on cooperatives in relation to all circularity strategies. We ask how circular economy strategies and business models resonate with cooperatives. The research is based on an exploratory database and survey of 165 cooperatives in the Canadian province of Québec. Our research shows circularity to be anchored in the mutualisation at the heart of the cooperative model, which emphasizes a shared taking of responsibility in response to needs. The survey shows that cooperatives contribute comprehensively to the circular economy, not just to downstream categories of recycling and revalorization but also to upstream categories of rethinking production and consumption, sharing, and durable use. They can contribute to an embedding of circular economy in regional economies and circular societies. To advance this potential, further integration and improvement of circularity strategies and associated socio-technical questions, support with business model development and finance, as well as education and peer exchange are needed.