The film was originally called "Imagination", which is the name of John Lennon's song of the same name (written in 1971). But the crew was not authorized to use it, and later changed the name to "Danny Collins". Fortunately, Lennon’s widow Yoko Ono allowed the film to use Lennon’s music.
When the film was planned for production in 2001, it was originally scheduled to star Steve Carell. Julianne Moore and Jeremy Renner both joined the cast, but withdrew due to film production delays.
The segments of the concert in the film were shot at the Greek Theater in Los Angeles. It was actually a concert by a Chicago band.
.Jennifer Garner has always regarded Annette Bening as her idol. Before cooperating in this film, she often mentioned the actress's name in interviews.
The script of the film is inspired by real events. An English folk singer named Steve Tilston received a letter from Lennon, many years after the letter was written. But in reality, Steve Tilston's story is not as dramatic as Danny Collins in the film.
