The producers asked George Takei to come back and play Sulu one more time, and take the helm of the Enterprise-B. But Takei refused, because if Sulu had taken the helm, this would have meant temporarily reducing Sulu's rank, so that he could serve under Captain Kirk again. He felt that Sulu had worked too hard to earn his command to allow even a temporary reduction. A new character, Demora, daughter of Sulu, was created to speak Sulu's lines.
The horse that William Shatner rides is his, as are the house and farm where the sequence takes place.
This was the first Star Trek film to be produced and filmed after the death of Gene Roddenberry. Following his death, the Star Trek creative team began using story ideas and concepts to which Roddenberry was opposed, which included the teaming up of Star Trek (1966) and Star Trek: The Next Generation (1987) characters.
Malcolm McDowell was so taken with the line "Time is the fire in which we burn", he had this engraved on the pocket watch he used in this film.
DeForest Kelley was set to appear in this film as Dr. Leonard "Bones" McCoy, but after reading the script and realizing that he would only appear at the film's beginning, he turned it down (also feeling that 'The Undiscovered Country' would be a better film to go out on). His lines were then given to Walter Koenig as Pavel Chekov. This is the reason that Chekov recruits two reporters as a makeshift medical staff and oversees the treatment of the rescued El-Aurians despite having no previously established medical training.
Tim Russ: The Vulcan security chief Tuvok on Star Trek: Voyager (1995) has a small role as a human member of the bridge crew of the Enterprise-B. In addition, he played the mercenary Devor in Starship Mine (1993).
Whoopi Goldberg: Reprising her role as the Enterprise's bartender Guinan from Star Trek: The Next Generation (1987), but is not credited in the cast list.
Jenette Goldstein: As a member of the bridge crew on the Enterprise-B. Goldstein was originally considered for the role of Tasha Yar on Star Trek: The Next Generation (1987), and her own performance in Aliens (1986) was the original inspiration for the role.
Patricia Tallman: The actress who plays Lyta Alexandar on the television series Babylon 5 (1993) is Gates McFadden's stunt double in this film. She can clearly be seen as Doctor Crusher falling off the sailing ship.
Patti Yasutake: Nurse Alyssa Ogawa from Star Trek: The Next Generation (1987) appears in a Sickbay scene, but has no spoken dialogue.