William Shatner conceived the film's story before he was officially given the director's job, drawing inspiration from televangelists whom he found 'repulsive, strangely horrifying, and yet absolutely fascinating.'

Shatner's first outline was titled 'An Act of Love,' and many of its elements, such as the Yosemite vacation and the hostage-taking on a failed paradise planet, survived into the final film.

Shatner wanted novelist Eric Van Lustbader to write the treatment, but negotiations failed over Lustbader's requested $1 million salary, so Shatner dictated the story himself.

Series creator Gene Roddenberry objected to the story's search for God, while Leonard Nimoy and DeForest Kelley disagreed with the idea that Spock and McCoy would betray Kirk, leading to multiple script revisions.

Sean Connery was originally offered the role of Sybok but was busy filming Indiana Jones and the Last Crusade; the mythical planet Sha Ka Ree was named as a wordplay on his name in his honor.

Shatner discovered Laurence Luckinbill for the role of Sybok by chance while channel surfing late one night and seeing him portray Lyndon B. Johnson; Luckinbill accepted the role immediately when called.

Todd Bryant, cast as Klingon Captain Klaa, was offered the role while playing ping pong at a beach party, and had to audition twice, the second time speaking in Klingon at Shatner's request.

David Warner agreed to play the Federation ambassador without auditioning, only after Shatner swore that his character would survive the film.

George Murdock was originally intended to play the Klingon diplomat Korrd, but Shatner changed his mind after seeing Charles Cooper's performance and recast Murdock as the 'God' entity instead.

Shortly before location shooting, Hollywood Teamsters went on strike, and after a production camera truck exploded in a parking lot, non-union drivers drove to Yosemite under cover of darkness with a police escort.

Stuntman Ken Bates set a record for the highest American descender fall by plummeting off El Capitan with a wire support rig for the film's climbing sequence.

During filming in the Mojave Desert's 110°F heat, Shatner 'cracked' on set, insulting the head electrician, and dehydrated extras moved at what he later called 'the Sybok shuffle.'

Because ILM's best crews were busy with Indiana Jones and the Last Crusade and Ghostbusters II, the production hired Bran Ferren's company Associates and Ferren, which had only three months (half the usual time) to complete the effects.

The film's climactic 'Rockman' creature was a fire-breathing latex rubber suit that malfunctioned on the last day of desert shooting, prompting the crew to replace it in post-production with an unsatisfactory 'amorphous blob of light and energy' effect.

The 'God column' effect was created using a rapidly rotating cylinder with light shone through it, with actor George Murdock's face projected into it via a beam splitter.

Composer Jerry Goldsmith, who had scored Star Trek: The Motion Picture, returned for The Final Frontier and reused the march theme from that earlier film, which confused Star Trek: The Next Generation fans unfamiliar with its origin.

The Final Frontier had the highest opening weekend gross of any Star Trek film to that point, but its box office dropped 58% in its second week and it ended up as one of the summer's biggest box-office disappointments.