For more than 30 years, scientists and technologists have been experimenting with augmented reality (AR) applications, projecting words and imagery into the real world for both practical and fantastical purposes. Until recently, AR use beyond the laboratory had largely remained limited to military and corporate clients with complex training needs and generous budgets. Recent technological innovations, such as the widespread adoption of smartphones and portable tablets, the development of eyeglasses with electronic properties, and the creation of AR-content authoring toolkits, increase the feasibility of using AR to help more people learn in more ways. In light of this shift, this entry considers the opportunities and challenges of designing AR for learning from childhood through adulthood, briefly synthesizing research from applied psychology, education, and engineering. This ...