Paul Newman's charity for children with serious medical conditions is named Hole in the Wall Camp after Butch's gang.
Katharine Ross enjoyed shooting the silent bicycle riding sequence best because it was handled by the film crew's second unit rather than the director. She said, "Any day away from George Roy Hill was a good one." This was after she had been scolded and banned from the set by Hill for operating a camera, even though cinematographer Conrad Hall, who Ross was dating, invited her to do it. Hall wasn't punished by Hill for letting her.
On the first day of shooting, involving the train robbery scenes, Katharine Ross came to the set to watch. There were five cameras and only four operators, so cinematographer Conrad L. Hall put her on the extra camera. He showed her how to operate it and how to move it to get her shot. Director George Roy Hill was furious, but said nothing the whole day. At the end of the day, however, he banned her from the set except when she was working.
The song "Raindrops Keep Fallin' on My Head" was written after the rough cut was completed, and when Robert Redford first saw it in the movie, he thought it was terrible. The agents for singer B.J. Thomas regretted letting him do it, and thought it would ruin his career.
Paul Newman sawed George Roy Hill's desk in half "because he wouldn't pay his bill for liquor which he borrowed from my office."