Jack Kornfield (born 1945) is an American writer and teacher in the Vipassana movement in American Theravada Buddhism. He trained as a Buddhist monk in Thailand, Burma and India, first as a student of the Thai forest master Ajahn Chah and Mahasi Sayadaw of Burma. He has taught mindfulness meditation worldwide since 1974. In 1975, he co-founded the Insight Meditation Society in Barre, Massachusetts, with Sharon Salzberg and Joseph Goldstein, and subsequently in 1987, Spirit Rock Meditation Center in Woodacre, California. Kornfield has worked as a peacemaker and activist, organized teacher training, and led international gatherings of Buddhist teachers including the Dalai Lama.
