This chapter discusses audio description (AD), which is an audiovisual translation method whereby images are translated into words. AD is primarily created with blind and visually impaired persons in mind, though it can also benefit people with no sight loss. The chapter starts with the definition of AD and its typologies, as well as with the discussion of its primary and secondary target audiences. This is followed by presentation of the main AD types: screen AD, (semi-)live AD and museum AD. Next, a short historical overview is offered, followed by the theoretical foundations and research which includes text-based, reception and experimental studies. The chapter ends with some didactic implications and an attempt to predict some future trends including those related to the Universal Design (UD) paradigm and the idea of an inclusive society.