Last week on Star Trek: Strange New Worlds in the episode “Tomorrow and Tomorrow and Tomorrow,” La’An Noonien-Singh (Christina Chong) traveled to the 2020s to restore the timeline. For this week’s edition of Trek Tuesday, Geek Girl Authority is going where many Star Trek crews have gone before: through time itself.

Here are 10 Star Trek time travel episodes. However, there are so many Trek time travel episodes this barely scratches the clock’s face. Be sure and let us know if we included your favorite.

“The City on the Edge of Forever”

Captain James T. Kirk (William Shatner) and Mr. Spock (Leonard Nimoy) stand before the Guardian of Forever on Star Trek: TOS.

The Star Trek: The Original Series Season 1 episode “The City on the Edge of Forever” is considered one of the best time travel stories ever told. This episode was made from a script originally written by Harlan Ellison (which received uncredited punch-ups from D.C. Fontana). It introduces the Guardian of Forever. This time travel portal has become integral to the Franchise in the intervening decades.

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In “The City on the Edge of Forever,” Captain James T. Kirk (William Shatner) and Mr. Spock (Leonard Nimoy) enter the Guardian of Forever and visit 1930s New York City. They are in pursuit of Doctor Leonard “Bones” McCoy (DeForest Kelley). Under the influence of an accidentally-administered psychoactive medical treatment, McCoy threatens to create a parallel timeline where the Federation’s future never comes into being. The episode also features Joan Collins as the ill-fated 20th-century visionary Edith Keeler.


Spock (Leonard Nimoy) rides his pet sehlat against a stormy Vulcan sky.

The Guardian of Forever returns in the Star Trek: The Animated Series Season 1 episode “Yesteryear.” In this episode, only Spock enters into the time travel portal. On the other side, he visits his childhood. This allows Trekkies to learn the story of Spock’s childhood pet, a sehlat named I Chaya.

Spock’s sehlat was previously mentioned in the TOS episode “Journey to Babel.” Just like that episode, this one features a guest appearance by Spock’s father, Sarek (Mark Lenard). This essential episode in Spock’s Franchise-spanning narrative arc was written by Fontana. 

“Yesterday’s Enterprise”

Tasha Yar (Denise Crosby) looks intense as she sits on the bridge of the Enterprise-C in Star Trek: TNG's "Yesterday's Enterprise."

In the Star Trek: The Next Generation Season 3 episode “Yesterday’s Enterprise,” the USS Enterprise-C travels through a time portal and arrives in TNG‘s present day. This creates an alternate timeline in which the crew and timeline of the familiar Enterprise-D are altered. Captain Jean-Luc Picard (Patrick Stewart) may still be in command of the Enterprise-D. However, he is a distinct Picard variant, not the Picard that Trekkies know and love.

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Fortunately, Guinan (Whoopi Goldberg) and her special talents as an El-Aurian allow for the restoration of the more familiar timeline. Furthermore, Guinan’s meta-sense that Tasha Yar (Denise Crosby) is destined to meet a pointless death allows for the survival of Yar’s time-travel duplicate. 

“Trials and Tribble-ations”

In the foreground are Captain Kirk (William Shatner) and Spock (Leonard Nimoy). In the background are Sisko (Avery Brooks) and Jadzia (Terry Farrell). They are all in the hallways of the TOS era Enterprise.

In the Star Trek: Deep Space Nine Season 5 episode “Trials and Tribble-ations,” the crew of the USS Defiant becomes involved in a plot to kill Kirk orchestrated by a time-traveling Klingon with his sights set on the 2260s. This results in their travel back in time to the events of the TOS season 2 episode “The Troubles with Tribbles.” Ultimately, the Defiant crew is able to ensure the integrity of the timeline.

This episode reuses footage from “The Trouble with Tribbles” to seamlessly integrate the crew of Kirk’s Enterprise into the episode. Plus, it features the return of Charlie Brill as Arne Darvin, a part he originally played in the TOS episode. This episode also introduces the Department of Temporal Investigations.


An older, white-haired version of Janeway (Kate Mulgrew) speaks with present-day Janeway aboard the USS Voyager.

Temporal Prime Directive? Admiral Kathryn Janeway (Kate Mulgrew) doesn’t need any stinking Temporal Prime Directive. In the feature-length series finale of Star Trek: Voyager, an alternate-future Janeway travels back in time to help the USS Voyager return home ahead of schedule.

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As a result, future Federation technologies are brought back several decades. As implied by the tech on Star Trek: Prodigy, this causes alterations to the timeline. Other timeline alterations include the survival of Chakotay (Robert Beltran) and a successful attack on the Borg Queen (Alice Krige). As seen in the series finale for Star Trek: Picard, the alternate Janeway’s attack on the Borg has lasting implications for the timeline.

“Future Tense”

Malcolm Reed (Dominic Keating), Captain Jonathan Archer (Scott Bakula), and T'Pol (Jolene Blalock) examine the future craft on Star Trek: Enterprise.

The crewmembers of the NX-01 Enterprise were not strangers to time travel. In fact, they were even unwillingly involved in an unresolved Temporal Cold War. However, in the Star Trek: Enterprise Season 2 episode “Future Tense,” the Enterprise isn’t the spacecraft that’s traveled back in time.

In “Future Tense,” Enterprise encounters a craft that features impossible future technology, including being “bigger on the inside than it is on the outside.” Soon, the Suiban and Tholains become embroiled in a battle for control of the future ship. However, the crew 0f the Enterprise is ultimately successful in destroying it (or at least knocking it out of their temporal frame). This episode also reveals that humans and Vulcans will eventually exchange chromosomes.

“That Hope is You, Part 1”

Cleveland "Book" Booker (David Ajala) and Michael Burnham (Sonqeua Martin-Green) stand beside one other. They are wearing 31st century clothing.

The Star Trek: Discovery Season 1 premiere “That Hope is You, Part 1” travels to the distant future. Picking up where the Discovery Season 2 finale left off, this episode follows soon-to-be-Captain Michael Burnham (Sonequa Martin-Green) as she travels hundreds of years into the future. But after arriving in the 31st Century, Burnham finds that her beloved Federation no longer carries the same influence it did in the 23rd Century.

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This episode introduces fan-favorite characters Cleveland “Book” Booker (David Ajala) and his counterpart, Queen Grudge (Leeu and Durban). Plus, it’s very interesting that “That Hope is You, Part 2” is not the second episode of the season but rather the season 3 finale.


The Borg Queen (Annie Wersching) assimilates the La Sirena in Star Trek: Picard season 2's "Assimliation."

Technically, all 10 Picard Season 2 episodes could qualify for this list. However, “Assimilation” is the episode in which Picard and his crew travel back in time to 2024. They undertake the same slingshot technique previously utilized by Kirk’s crew to accomplish this. However, without the mental faculties of Spock, they must instead rely on the Borg Queen (Annie Wersching). What could possibly go wrong?

As a special time-travel bonus, this episode was directed by Lea Thompson. While Thompson is a self-avowed life-long Trekkie, she may be best known for her role in the Back to the Future trilogy. This is only one of the many time-travel Easter eggs in Picard season 2, which also features multiple callbacks to Star Trek IV: The Voyage Home.

Star Trek: Lower Decks

Ensigns Samanthan Rutherford (Eugene Cordero,) Bradward Boimler (Jack Quaid), Beckett Mariner (Tawny Newsome), and D'Vana Tendi (Noël Wells) on the bridge of the Wayfarer in Star Trek: Lower Decks season 3's "Crisis Point 2: Paradoxus."

Technically, Star Trek: Lower Decks has yet to have an actual time travel episode. However, series creator Mike McMahan told GGA that the show “will handle time travel, probably more than once.” It’s possible this may transpire in the upcoming crossover episode between Lower Decks and Strange New Worlds. However, several allusions have been to time travel on Lower Decks so far. In the Lower Decks Season 3 episode “Mining the Mind’s Mines,” Ensigns Samanthan Rutherford (Eugene Cordero) and Bradward Boimler (Jack Quaid) can’t remember whether or not Beta Shift’s exploits (so far) have included time travel.

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Meanwhile, the Lower Decks Season 3 episode “Crisis Point 2: Paradoxus” features a simulated time travel story on the Holodeck. After learning the story concerns time travel, Ensign Beckett Mariner (Tawny Newsome) states they are not traveling back in time to assassinate Kennedy. This alludes to an unproduced pitch for a Star Trek movie by Gene Roddenberry in which Kirk and crew must deal with time-traveling Klingons with their sights set on disrupting Earth’s history in the early 1960s.

“Time Amok”

Rok-Tahk (Ryliee Alazraqui) and Hologram Janeway (Kate Mulgrew) discuss the timeline in Star Trek: Prodigy.

In the Prodigy Season 1 episode “Time Amok,” the crew of the Protostar are knocked into separate and distinct temporal phases. As a result, they are all trapped in the same time frame but cannot interact with one another because they are each experiencing the passage of time at a different distorted rate.

Ultimately, the crew is able to restore the passage of time to normal thanks to teamwork. This is enabled by Hologram Janeway (Mulgrew) and her ability to traverse multiple time frames.

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Avery Kaplan