In 1969, Captain Nemo's pipe organ, which had been on display in Disneyland, was redressed and now resides in the ballroom of Disneyland's Haunted Mansion. A duplicate was constructed for the ballroom of Walt Disney World's Magic Kingdom Haunted Mansion, which opened in 1971, and over a decade later another duplicate was built for Tokyo Disneyland.

Walt Disney briefly considered English actor Ralph Richardson for the role of Captain Nemo.

Richard Fleischer was surprised at being considered for the director's chair for this film, as he was the son of Disney's biggest competitor, Max Fleischer. He approached Walt Disney to inquire if Disney knew who he was. Disney told him that he was well aware of who he was and hired him because he thought he was the best man for the job. Richard Fleischer also asked his father if he minded having his son working for his rival but Max Fleischer made no objection and even asked Richard to tell Disney that he thought he had made an excellent choice for his director!

Peter Lorre claimed that the giant squid got the role that was usually reserved for him.

According to Kirk Douglas in his autobiography, "Ragman's Son", the scene at the beginning of the film where Ned Land strolls up (with a beautiful girl on each arm) to the lecturing sailor - and the ensuing fight - was written into the film at his request. At the time this film was shot, Douglas was in the prime of his career and very concerned about promoting and preserving his reputation with the movie-going public as both a dashing ladies man and a "macho" actor known for tough, physical roles that showcased his image as an action hero (fight scenes and so forth). When he first read the first draft script for this film, he was somewhat disappointed to find that his character Ned Land made no appearances with any women whatsoever, had no real rousing fight scenes, other than the battle with the squid, and spent most of the movie talking instead of being in action. Having expressed these concerns both to Walt Disney and director Richard Fleischer, the San Francisco street scene at the beginning of the film - featuring his character involved with two beautiful women in addition a rousing action/fight scene - was added especially for him (in at least two later films Douglas also made sure his character would be seen with two beautiful women at the same time and be inv