Gregg Elliott was born in 1938 in New York to a large Irish-Catholic family. In his teens he strongly considered joining the priesthood but decided instead to join the military reserves while attending college. He ultimately served 27 years in the service, married, and had four children. After retirement, he continued his education and worked as a chaplain for hospitals and hospices.

A few years after being widowed he decided to achieve his former dream of becoming a priest. He was given the pastorship of a small Oklahoma parish which he maintained for 8 years. When the need presented itself for a Catholic priest to advise Terence Malick, the director of To The Wonder, his attention was directed to Father Gregg. Malick also gave him a small role in the film.

He is now semi-retired, enjoying time with his family.