Digital health literacy (DiHL) is a new and evolving concept. Given the ongoing digitalization of health, social and other systems, and the shift of health-related information and communication exchange into the digital space, it is becoming an increasingly important qualification for citizens, but also for health workers. The DiHL concept has recently begun to move away from being solely an issue for individuals or patients to an issue for populations and health providers. Privacy and ethical issues associated with digital technology use and data sharing are also closely related to digital health literacy. The chapter provides an overview of the field, moving from definitions and the evolution of the underlying concept to an overview of core instruments for the assessment of digital health literacy, with selected results on empirical findings from various populations. After discussing critical aspects of current concepts and available knowledge on digital health literacy levels, we provide an outlook that goes beyond enhancing not only individual capacities but also organizational digital health literacy.