According to director Ken Russell's DVD commentary, Sir Elton John initially turned down the part of the Pinball Wizard. One of those seriously considered for the role was David Essex, who had played Tommy in the 1973 stage production and recorded a version of the Pinball Wizard at his home studio. However, producer Robert Stigwood held out to get John, who finally agreed to play the role, on the condition that he could keep the oversized Doc Martin boots from his costume.
According to Pete Townshend, Oliver Reed had incredible problems recording his part of the soundtrack owing to his inability to sing, and he was able to complete it only because his singing parts were recorded in small bits. Because of this frustrating experience, Townshend was extremely suspicious towards Jack Nicholson when he was chosen to the role of the doctor. Townshend, however, finally agreed when he heard Nicholson singing effortlessly.
Eric Clapton appears in the film as a favor for Pete Townshend, who helped him kick his heroin addiction.
Ann-Margret largely improvised the infamous bean scene. Director Ken Russell simply told her that her character was having a nervous breakdown, and that she could do whatever she wanted. Unfortunately, at one point during filming, her hand accidentally struck the broken glass of the television screen, and Russell had to rush her to the hospital for stitches.
Barry Gibb: Person who pushes one of the wheel chairs during "Eyesight to the Blind/Marilyn Monroe" sequence.
Ken Russell: One of the disabled people during the Eyesight to the Blind sequence. He also can be seen in the Tommy's Holiday Camp sequence in the junkyard at the end of the film. He's in a wheelchair.
Ken Russell: [colors] Colors of sets during "Acid Queen", "Cousin Kevin", and "Uncle Ernie" sequences; lighting during "Pinball Wizard".