Purpose The purpose of this study is to investigate how consumer brand engagement may be improved by conveying sustainability in an omnichannel setting. Design/methodology/approach This research focuses on luxury fashion brands, presenting a multiple case study of four Italian luxury fashion brands highly committed to sustainability. Findings It demonstrates the vital role that omnichannel communication plays in conveying sustainable brand behaviours to increase consumer brand engagement and the beneficial influence on positive word of mouth, a sense of community and helpfulness. Originality/value This study identifies strategies in omnichannel sustainability communication to increase consumer engagement with luxury fashion brands.