Personalisation involves specialisation achieved by differentiating and often customising products, services, experiences and communications for a specific individual. In fashion marketing, personalisation is particularly characterised by a spectrum of customised and bespoke processes and practices. This is in part driven by increased individualism and sense of individual identity among consumers, but also by self-defining through the personalisation of things and the extension of the self. For marketers, an awareness of consumers’ needs for self-identity and image forms an important driver for the personalisation of fashion: ever-finer market segmentation and differentiation logically leads to markets of one. For fashion marketers, customer value provides an overarching framework for personalisation, in particular, value-creating activities through producer–consumer engagement in the personalising process. Many of these characteristics are inherent in customer relationship management (CRM), which contributes to a framework of relationship-building, loyalty and value. The chapter continues with an exploration of customisation and co-creation not only of products but also of marketing communications, online collaborations with consumers and the use of social media. It concludes with a discussion of personal data and the role of AI in personalisation, in which the need to build trust, eliminate bias and ensure privacy and security are essential elements.