Circular business models (CBMs) balance economic, social, and environmental value creation, capture, and delivery. They incorporate strategies to slow down, narrow, or close resource loops in opposition to the current linear ‘take-make-waste’ model of production and consumption, thereby advancing the transition to a more circular and sustainable economy. This transition, however, is not easy and involves great uncertainty – not in the least because these business models involve a multitude of actors in networks and ecosystems who may be reluctant to participate in or who might even obstruct the circular transition. In this paper, we call for a new approach to inform and guide the development and adoption of these CBMs, specifically through boosting “circular economy engagement” (i.e., an actor’s disposition to embrace CBMs). We conduct a systematic literature review of 133 CBM papers using the Motivation-Opportunity-Ability (MOA) framework as an organizing structure in order to uncover the conditions under which different actors – firms, customers, and governmental bodies – engage in the circular economy. From there, we propose a conceptual framework illustrating how motivation-related, opportunity-related, and ability-related practices are able to boost actors’ circular economy engagement. Specifically, we highlight and illustrate the role of (1) signaling and convincing as motivation-related practices, (2) matching and legitimizing as opportunity-related practices, and (3) supporting and empowering as ability-related practices. Finally, we discuss several theoretical and practical implications connected to this framework and identify several remaining challenges for advancing the circular transition.