Leslie Greenberg, Ph.D. is Distinguished Research Professor Emeritus of Psychology at York University in Toronto. He was originally trained in Person Centered and Gestalt therapy and engaged in psychotherapy research. He has authored the major texts on Emotion Focused Therapy from the first books Emotion in Psychotherapy (1986) and Emotionally Focused Therapy for Couples (1988) to most recent Emotion-Focused Therapy (2015) and Emotion focused therapy of Forgiveness and Letting go (2019). He has received both the Early Career and the Distinguished Research Career award of the International Society for Psychotherapy Research as well as the Carl Rogers and the Distinguished Professional Contribution to Applied Research of the American Psychology Association. He also has 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. He now spends the majority of his time training people in emotion–focused approaches.