This study explores drivers of supply chain sustainability during COVID-19 in both the Australian and Saudi Arabian fashion industries. COVID-19 is the most recent global crisis to amplify sustainability issues in a very polluting sector. This qualitative, comparative study draws on 44 semi-structured interviews with fashion brands across the fashion spectrum, evenly distributed between Australia and Saudi Arabia. A grounded approach to analysis was applied. Findings indicate reactive and proactive approaches to dealing with COVID-19 and its impacts. A reactive approach, or dealing with a situation when faced with it, is guided by isomorphic pressures, which are classified as external forces that shape and influence how an organisation operates within society, but also can lead to changes in internal practices. A proactive approach implies foresight and acts upon a situation prior to being ‘forced’ to make changes and encourages social sustainability along the supply chain. To overcome challenges intensified by the pandemic, fashion organisations need to increase flexibility and collaborative approaches. This study makes a novel contribution to the literature through its cross-cultural comparison, exploring sustainability drivers with institutional theory.