Leslie S. Greenberg, PhD, is Distinguished Research Professor Emeritus of psychology at York University in Toronto, Canada and the primary developer of emotion-focused therapy. He has authored many books, the most recent being Changing Emotion with Emotion (2021). He has received the Distinguished Research Career Award of the International Society for Psychotherapy Research, as well as the Distinguished Professional Contribution to Applied Research from the American Psychology Association. Dr. Greenberg has also received the Canadian Psychological Association Professional Award for Distinguished Contributions to Psychology as a Profession. He is a past president of the Society for Psychotherapy Research. Although retired, Dr. Greenberg is still currently training and supervising people internationally in emotion-focused approaches.