List of Star Trek: The Original Series episodes

Pilots (1964–65)

Star Trek's pilot episode, "The Cage", was completed between November 1964 and January 1965, and starred Jeffrey Hunter as Captain Christopher Pike, Majel Barrett as Number One, and Leonard Nimoy as Spock. After the pilot was rejected by NBC as being "too cerebral" (among other complaints), Jeffrey Hunter chose to withdraw from the role of Pike when creator Gene Roddenberry was asked to produce a second pilot episode ("Where No Man Has Gone Before") of which an edited version of the same name aired in 1966.

"The Cage" never aired during Star Trek's original run on NBC. It was presented by Roddenberry as a black-and-white workprint at various science fiction conventions over the years after Star Trek's cancellation but was not released on home video until 1986 when Paramount Home Video produced a "restored" release of "The Cage" (a combination of the original black-and-white footage and color portions of the Season 1 episode "The Menagerie") complete with an introduction by Gene Roddenberry.

On October 4, 1988, Paramount Pictures aired a two-hour television special, hosted by Patrick Stewart, called The Star Trek Saga: From One Generation to the Next, which featured, for the first time, a full-color television presentation of "The Cage". In some markets, the special did not air until October 15, 1988. In the United States, "The Cage" was first released to DVD in December 2001. It was later included on the final disc in both the original and "remastered" Season 3 DVD box sets (listed with the original air date of October 15, 1988).

The also planned-as-pilot "Where No Man Has Gone Before" in its original form (production number 02a) had been forwarded to NBC, but only a re-worked, re-edited, re-formatted, cut version was later aired under the same name, not as a pilot but as the third episode of the series (production number 02b). Afterwards, over the years the original "alternate" version was thought to be lost but later appeared as bootleg VHS tapes at conventions, until a print of it was discovered in 2009 and subsequently released on home video under the title "Where No Fan Has Gone Before" - The Restored, Unaired Alternate Pilot Episode as part of the TOS season 3 box set on Blu-ray; it has not been released on DVD yet. This version remains unaired.

Season 1 (1966–67)

After Roddenberry's second pilot episode, "Where No Man Has Gone Before", received a more favorable response from NBC, Star Trek finally aired its first episode—"The Man Trap"—at 8:30PM on September 8, 1966. "Where No Man...", which eventually aired in a re-edited format as the series' third episode, retained only Spock as a character from "The Cage" but introduced William Shatner as Captain Kirk, James Doohan as chief engineer Scotty, and George Takei as physicist (later helmsman) Sulu. Also joining the cast were DeForest Kelley as ship's surgeon and Nichelle Nichols as the communications officer Uhura in "The Man Trap"; the first aired episode of the series.

Although her character of Number One was not retained from "The Cage", Majel Barrett returned to the show as a new character, nurse Christine Chapel, and made her first of many recurring appearances in "The Naked Time". Grace Lee Whitney appeared in eight episodes as yeoman Janice Rand, beginning with "The Man Trap". Whitney left the series after "The Conscience of the King", but would later make minor appearances in the first, third, fourth, and sixth Trek films as well as one episode of the companion series Star Trek: Voyager.

Star Trek's first season comprised 29 episodes, including the two-part episode "The Menagerie", which includes much of the footage from the original pilot, "The Cage". Other notable episodes include "Balance of Terror", which introduces the Romulans; "Space Seed", which introduces Khan Noonien Singh and serves as the basis for Star Trek II: The Wrath of Khan; "Errand of Mercy", in which the Klingons make their first appearance; and the critically acclaimed, Hugo-Award-winning episode "The City on the Edge of Forever", which features Kirk, Spock, and McCoy traveling into the past through the Guardian of Forever.

Season 2 (1967–68)

The show's 26-episode second season began in September 1967 with "Amok Time", which introduced actor Walter Koenig as Russian navigator Pavel Chekov, and granted viewers the first glimpse of Spock's homeworld, Vulcan. The season also includes such notable episodes as "Mirror, Mirror", which introduces the evil "mirror universe"; "Journey to Babel", featuring the introduction of Spock's parents Sarek and Amanda; and the light-hearted "The Trouble with Tribbles", which would later be revisited in a 1973 episode of Star Trek: The Animated Series and a 1996 episode of Star Trek: Deep Space Nine. The season ended with Assignment: Earth, an attempt to launch a spin-off television series set in the (then) present day.

Season 3 (1968–69)

After Star Trek's second season, NBC was prepared to cancel the show due to low ratings. Led by fans Bjo and John Trimble, Trek viewers inundated NBC with letters protesting the show's demise and pleading the network to renew the series for another year. After NBC agreed to produce a third season, the network promised Gene Roddenberry that the show would air in a favorable timeslot (Mondays at 7:30 PM), but later changed the schedule so that Trek would air in the so-called "death slot" — Friday nights at 10:00PM. In addition to the "mismanaged" schedule, the show's budget was "seriously slashed" and Nichelle Nichols described the series' eventual cancellation as "a self-fulfilling prophecy".

Star Trek's final, 24-episode season began in September 1968 with "Spock's Brain". The third season also includes "The Tholian Web", where Kirk becomes trapped between universes; this episode would later be revisited by two 2005 episodes of the prequel series Star Trek: Enterprise. The last episode of the series, "Turnabout Intruder", aired on June 3, 1969, but Star Trek would eventually return to television in animated form when the animated Star Trek debuted in September 1973.

Production order

The list below details the series' episodes in production order, including the original series pilot, "The Cage". While the "complete season" DVD releases (listed above) follow the original broadcast order, the original episodic DVD releases are numbered by production order.

British transmission

Star Trek was first broadcast in the UK on BBC One starting on July 12, 1969 with the episode "Where No Man Has Gone Before". The first episode broadcast in color was "Arena" on November 15, 1969. The running order was very different from the US original with the episodes being shown in four seasons between 1969 and 1971. The Cage was first transmitted on Sky One in July 1990 and three episodes, "Plato's Stepchildren", "The Empath" and "Whom Gods Destroy" were not broadcast on the BBC until early 1994. Sky One were the first to show them in their run that started in 1990 (though Sky were supplied with the BBC edited versions of the series) and tellingly the three "banned" episodes were the only ones that had the opening titles in the right place, having never been shown by the BBC although "The Empath" is listed for transmission on Wednesday December 16, 1970 at 7.20pm in the Radio Times.

The BBC broadcast versions of the episodes differed from the way they had been shown in America. The opening elements of each episode were transposed so that the title sequence was the first thing seen, followed by the teaser, and then into the rest of the episode without a pause. These prints were used up until the 1990s but for their new run the BBC were supplied with NTSC tape transfers instead of new film prints. This resulted in the odd blurry appearance that viewers were getting used to on new US shows at the time. Season one was shown and at least some episodes had edits that matched the syndication cuts of the US episodes "The Menagerie" Part 1 for instance. Viewers complained and the BBC obtained film prints from season two, although for some reason the old edited version of "The Deadly Years" was shown in the first '90s repeat.