Mind Meld: Secrets Behind the Voyage of a Lifetime is a 2001 American documentary film in which actors William Shatner and Leonard Nimoy discuss the Star Trek science fiction franchise and its effects on their lives. Shatner and Nimoy portrayed the characters James T. Kirk and Spock respectively in the 1960s Star Trek television series, the 1970s animated television series, and their film sequels.

They talk about differences they had with Gene Roddenberry, the creator of Star Trek, and about the strained relationships between Shatner and some of the other cast members. It was in this film that Nimoy first publicly revealed that he had struggled with alcoholism while he was acting in the original television series. Shatner talks about the death of his third wife, Nerine Kidd, who accidentally drowned in a pool in 1999 after suffering from alcoholism.

Mind Meld was produced to advertise Shatner's personal website. Filming took place at Nimoy's home on September 5, 2001, and Billy West narrated the title sequence. The film's title refers to a fictional practice in Star Trek—a mind meld is a telepathic link that Vulcans are able to create with other organisms. Mind Meld was released for sale on Shatner's website on November 6, 2001, coinciding with the release of the director's cut of Star Trek: The Motion Picture. Mind Meld attracted some notoriety because of an unintended sound in one scene that became a popular subject of flatulence humor among Star Trek fans and on morning zoo radio programs. Shatner denied being the source of this sound in multiple interviews; he and Mind Meld's director, Peter Jaysen, attributed it to equipment on set.

The film received mixed reviews from critics. Scott Brown of Entertainment Weekly gave the film an "F", and said that the only people likely to watch the film were extreme Star Trek fans and people interested in hearing Shatner's supposed flatulence. Laurence Lerman of Video Business praised the film for not "rehash[ing] anecdotes that have long been staples of Star Trek conventions and behind-the-scenes memoirs", and instead for dealing with such topics as alcoholism, career difficulties, and conflicts on the set of Star Trek.