Auditions for the title role spanned two years, 22 cities, 8,000 interviews, and 70 actresses. Nine young actresses made it to the second round.
Steve Martin was offered the role of Rooster. He turned it down when he heard he would be working alongside Bernadette Peters. They were breaking up at the time, and he felt it would be too painful to work with her for several months.
Production designer Dale Hennesy died in the middle of production. Gene Callahan agreed to finish the movie, but refused to have his name listed in the credits, giving the credit to the late Hennesy.
In the play, Grace Farrell brought the adoption papers to the orphanage. After the movie script had Oliver "Daddy" Warbucks do it, Carol Burnett and Albert Finney lobbied the songwriters for a song to sing together to flesh out the only meeting between Warbucks and Hannigan. Their duet, "Sign", was written in two days.
John Huston: The voice on Miss Hannigan's radio saying, "I love you, I love you, I love you," just before "Little Girls".