This book explores one way in which recent hardware and software advances have placed humanity on the precipice of a significant shift in how technology can shape our interactions with the world around us: the application of transformative extended reality (XR) technology solutions to support the health, wellness, quality of life, and independence of older adults living with and without cognitive impairments. The book provides an overview of the state-of-the art research on XR-based solutions utilizing virtual reality (VR) and augmented reality (AR), challenges that can addressed with these technologies, evidence to date on the efficacy of these solutions, and the nature of these solutions and challenges to their implementation. It explores practical ways XR can be integrated into health and lifestyle maintenance activities for older populations in a diversity of situations through thematic chapters using realistic personas and scenarios. These thematic chapters are organized around the AGE-WELL Challenge Area topics, including staying connected, healthy lifestyles and wellness, mobility, and cognitive health, as well as an additional emphasis on leisure. Other chapters provide guidance on important issues to consider when designing XR-based solutions for older adults, how to evaluate and test XR solutions, the implementation of the user-centered design process, and the book concludes by highlighting unanswered questions and future research directions. This book approaches XR for older adults with and without cognitive impairments from the authors' diverse research backgrounds in psychology, engineering, gerontology, and design. It will be of interest to academic and industry professionals as well as care providers considering the potential for XR interventions now and in the future.