The paper examines how omnichannel communication of sustainability of luxury fashion brands enhance consumer brand engagement. We propose a multiple case study of four Italian high-end fashion brands. The study advances the literature on sustainable luxury fashion and omnichannel communication and offers guidelines for managers to effectively communicate sustainability.

Sustainability issue has received growing attention from various stakeholders. To engage more people to participate in sustainable actions, the United Nations has promoted #actnow campaign since 2019. Among various sustainability initiatives and approaches, the UN’s #actnow campaign focuses on food and fashion sustainability since these two industries encompass various sustainability issues from production and post-consumption. By analyzing Twitter's big data, the study findings demonstrate that negative sentiment messages are powerful in driving the public’s engagement in social media message dissemination. The findings suggest that practitioners may use assertive and strong voice messages to lead consumers’ participation in sustainable message dissemination.