Computer applications, and especially the Internet, provide many people with disabilities with unique opportunities for interpersonal communication, social interaction, and active participation (including access to labor and entertainment). Nevertheless, rigid user interfaces often present accessibility barriers to people with physical, sensory, or cognitive impairments. Accordingly, user interface personalization is crucial to overcome these barriers, allowing a considerable section of the population with disabilities to have computer access. Adapting the user interface to people with disabilities requires taking into consideration their physical, sensory, or cognitive abilities and restrictions and then providing alternative access procedures according to their capacities. This chapter presents methods and techniques that are applied to research and practice on user interface personalization for people with disabilities and discusses possible approaches for diverse application fields where personalization is required: accessibility to the web using transcoding, web mining for eGovernment, and human-robot interaction for people with severe motor restrictions.