Harbhajan Singh (born as Harbhajan Singh Puri) (August 26, 1929 – October 6, 2004), also known as Yogi Bhajan and Siri Singh Sahib to his followers, was a yogi, spiritual teacher, and entrepreneur, who introduced Kundalini Yoga to the United States. He was the spiritual director of the 3HO (Healthy, Happy, Holy Organization) Foundation, with over 300 centers in 35 countries.