Bennett was born in New Zealand in 1969. His mother Jean Bennett was an Australian bikini model and father Ted Bennett a New Zealand singer. The family moved to Australia when Bennett was a few months old. Bennett's father is of Māori (specifically Te Arawa and Ngāti Kahungunu) and Irish descent. His mother is of Scottish descent. He was raised mostly between Sydney and Newcastle in Australia, where he attended Merewether High School. In 1986, Bennett returned to New Zealand to attend Te Aute College, where he played for the 1st XV. Upon returning to Australia, Bennett was chosen in the New South Wales Schoolboys Rugby Union Team. Interested in modern dancing, classical ballet, and piano, Bennett quit rugby to attend university to study dance and drama, then traveled to Los Angeles on a scholarship to attend the Lee Strasberg Theatre Institute. In an audience Q&A in Boston, Bennett talked about the car accident he experienced at a young age that killed his mother and brother and put him in a two-week coma. At that time, his girlfriend was a ballet dancer which got him into acting; he found it to be the medium in which to direct his emotions, saying, "Acting was my route to survival. "