This article describes an initiative undertaken by a coalition of psychologists (Coalition for Psychology in Schools and Education) from the American Psychological Association (APA) to identify the top 20 principles from psychological science relevant to teaching and learning in the classroom. This article identifies these principles and their basis in psychological science. In addition, it articulates each principle's relevance to teaching practices. The article lists all 20 principles and describes a subset of these by providing the information described previously.