This book demonstrates how resources taken from positive psychology can benefit both teachers and learners. Positive psychology is the empirical study of how people thrive and flourish. This book explores a range of topics, such as affectivity and positive emotions, engagement, enjoyment, empathy, positive institutions, a positive L2 self-system, as well as newly added Positive Language Education. Some papers in this collection introduce new topics such as the role of positive psychology in international higher education, a framework for understanding language teacher well-being from an ecological perspective, or positive institutional policies in language education contexts.