A circular economy (CE) addresses the shift in economic systems from an unsustainable linear approach to a sustainable circular approach through start-ups and entrepreneurial ecosystems (EE). A single level of focus on CE research limits an understanding of the mechanisms fostering a transition towards CE. We conduct a systematic review of the macro-meso-micro interconnections between start-ups and EE in CE using bibliometric and content analyses to scope the literature without time boundaries. This exercise led to 90 articles from the Web of Science and Scopus databases. We contribute to literature on entrepreneurship and CE by building an integrative multi-level framework linked to the just and safe planetary boundaries by bridging macro-level explanations (public policies, regulations and infrastructure) and the meso-level (circular supply chains and circular ecosystems) and micro-level (circular start-ups and circular business models). The framework highlights social and environmental sustainability challenges, and just and safe close-loop production patterns.