- "Andrew, if you hear any rumors flying around the Vatican you let me know, all right?"
- ―B. J. Harrison[src]
- "Oh no, no. Andrew has the true faith."
- ―Michael Corleone[src]
Andrew Hagen was the younger son of Tom and Theresa Hagen and the brother of Frank, Gianna and Christina Hagen. He was also the adoptive nephew and godson of Michael Corleone. He was also an ordained priest.
- "Godfather... I wanted to thank you for all you’ve done for me."
- ―Andrew Hagen to Michael[src]
Andrew Hagen grew up in New York and was present at the wedding of his aunt Connie to Carlo Rizzi. His uncle Michael Corleone was his godfather. From a young age, he was deeply introspective, becoming a divinity major at the University of Notre Dame. His father Tom worried that he only wanted to become a priest to atone for his family's sins.
He was ordained as a Catholic priest shortly after his father's death and never became involved in the "family business". He and his mother attended family events such as the after party after Michael Corleone is given Order of Saint Sebastian. Several years later he was transferred to a prestigious post in the Vatican as a favor to Michael Corleone from Archbishop Gilday. He also attends the opera debut of his cousin Anthony, although the event was overshadowed by the murder of his cousin Mary. Andrew is shocked by the murder and prays. Afterwards, he attempts to comfort his uncle Michael, to limited effect.