Humanity has experienced significant economic growth since the industrial revolution, driven by the linear economy which promotes wealth growth through the "extract-make-consume-dispose" approach. However, this model has led to increased ecological footprints, climate issues, and social injustice. To mitigate these negative impacts, various organizations and governments advocate for the circular economy, which aims to minimize resource input and waste through practices like recycling, reuse, and remanufacturing. This PhD research explores the transition from linear to circular business models, emphasizing the importance of actor engagement in circular business model innovation. It aims to provide insights into how companies can shift to circular business models by engaging customers and other stakeholders.