<p>Industry 4.0 (I4.0) technologies associated with Circular Economy (CE) practices emerge as a promising solution to the challenges that arise at the intersection of technological advancement and sustainability. Despite attempts in the literature to relate these two complex themes, authors have focused on identifying drivers, enablers, and barriers, with few concrete examples of how these elements are interconnected, particularly regarding the integration between the key I4.0 technologies and CE practices. This study aims to understand the current state of research on the relationship between I4.0 and CE, identifying the most relevant technologies and practices while exploring their direction of influence. To achieve this, a multimethod approach was applied, starting with a Systematic Literature Review (SLR) to understand the current knowledge and identify the main I4.0 technologies and CE practices that are interconnected. Following the ISM/MICMAC methodology was adopted and operationalized by expert opinions to explore the direction of influence between I4.0 and CE. The results indicate that some technologies, (Internet of Things, Big Data Analytics, Artificial Intelligence, and Additive Manufacturing), are related to the Rs principles of CE (Recycle, Reuse, Remanufacture, Recover, and Reduce). The ISM/MICMAC indicates that I4.0 technologies can enhance CE practices, suggesting a collaboration that creates a sustainable and competitive paradigm. The analysis reveals that I4.0 technologies have a more significant influence on CE practices than the other way around, providing insights on how to maximize their use to achieve circularity. The study ends by proposing a research agenda for further investigation.</p>