Circular economy, circularity, and sustainability: A systematic review and conceptual framework

Circular economy (CE), circularity, and sustainability are conceptually distinct yet intrinsically interconnected frameworks that collectively offer transformative potential for addressing global environmental, economic, and social challenges. While each has received substantial scholarly attention, their integrative relationships and cumulative implications remain under-theorized and operationalized. In particular, the link between circularity (the extent to which materials and products circulate within closed loops) and broader sustainability outcomes lacks systematic examination. This study presents a systematic literature review of 151 peer-reviewed articles retrieved from the Scopus and Web of Science databases following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA 2020) protocol. Through a critical synthesis and thematic analysis, this review evaluates foundational conceptual constructs, emergent research themes, and enduring conceptual and methodological gaps within the CE-circularity-sustainability nexus. In response, this review proposes a conceptual framework that elucidates the dynamic interlinkages among these concepts, thereby providing a structured pathway to guide interdisciplinary research, policy development, and strategic practice toward integrated and systemic sustainable development.