Internet of Things (IoT) is a global platform of Internet connected smart devices that have been argued to improve the supply chain integration (SCI). While the positive effect of IoT capability on SCI influencing supply chain and firm performance is empirically validated, exploratory study in this context is limited. Drawing upon the organisational capability theory, this study investigates the use of IoT in enhancing the integration of suppliers, customers and internal activities of the retail supply chain. Interviews of managers across Australian retail industry were analysed using Nvivo. The thematic analysis reveals the added capability of IoT that improves supply chain visibility, auto-capture and information sharing for greater SCI. The IoT-enabled integration capability demonstrates a positive effect on cost, quality, delivery, and flexibility of the entire supply chain and improves retail firm's sustainable performance with financial, social and environmental outcomes.