The fast fashion industry confronts substantial sustainability issues because of its high resource consumption and waste output. The literature reveals that past studies have less focused on circular practices in fast fashion supply chain. This study aims to identify and analyse the potential enablers of circularity within fast fashion supply chains, promoting sustainable production and consumption practices. Through a comprehensive literature review and expert consultations with 12 domain experts from academia, apparel manufacturing, and sustainability practices, sixteen enablers of circularity were identified. To understand the interrelationships and hierarchical structure among the identified enablers, Grey DEMATEL method was employed. The results from the study reveal that sound purchasing policies, reverse logistics and adoption of eco-friendly and recyclable packaging act as the most influential causal enablers, while selection of fibres and consumer awareness and acceptance of recycled, refurbished clothing emerge as key effect enablers. By mapping these interrelationships, the study offers actionable insights for fashion retailers, policymakers, and sustainability practitioners to strengthen circular strategies. The findings contribute to advancing circular economy theory in the fashion sector and provide a practical framework for accelerating the transition towards sustainable and circular business models in fast fashion.