This chapter conceptualises the retail design process in the context of the sustainability imperative citing omnichannelling as its enabler, thus highlighting the role of retail design in mainstreaming circular economy (CE). In recent years, retail design has distinguished itself as a transdisciplinary profession addressing retailer and customer interactions across physical and virtual space (Quartier, 2015). Digitisation has transformed the customer from a passive partaker to an active participant with high expectations. Concurrently, fashion merchandise has become the most purchased products online, and the sustainability challenges surrounding this sector have also increased (Boström & Micheletti, 2016; Maccan, 2016). Intrinsically thriving on change, the fashion industry is dependent on a large material throughput generating considerable amounts of waste. This is exacerbated by the rapidly increasing global population which is demanding more fashion, goods, and services, putting strain on natural resources and affecting climate change whilst challenging current systems of production and consumption (Andrews, 2015; Boström & Micheletti, 2016). There is consensus in the fashion industry that a circular approach can lead to greater sustainability of this sector (Ellen MacArthur Foundation, 2017; Niinimäki, 2018). In its position between production and consumption, fashion retail has an important role to play in mainstreaming circularity by supporting fashion apparel utilisation rather than one-off sales.