A crossover is an event in a television franchise where characters from one series appear with the main characters and settings from another series. Many Star Trek crossovers served as introductions to the cast and setting of the latest show, while others were nostalgic reminiscences of previous series.
The following is a list of crossover characters who appeared first in one television or film series, and subsequently appeared in a different television or film series.
Characters are listed under the series in which they first appeared. Appearances by regular cast characters are not listed for the series in which they were regular cast.
Also note that a number of those listed below may not have necessarily had interactions with characters from the latter series, nor be live (vs. hologram, hallucination, etc.) versions of their former selves.
Star Trek: The Original Series[]
- James T. Kirk (series regular in Star Trek: The Animated Series and TOS films)
- Star Trek Generations
- DS9: "Trials and Tribble-ations" (archive footage)
- ENT: "These Are the Voyages..." (archive voice only)
- Star Trek Beyond (photograph)
- ST: "Ephraim and Dot" (archive voice only)
- LD: "No Small Parts" (photograph)
- SNW:
- "A Quality of Mercy" (alternate reality)
- "Tomorrow and Tomorrow and Tomorrow" (alternate reality and prime reality)
- "Lost in Translation"
- "Subspace Rhapsody"
- VST: "Walk, Don't Run" (non-canon) (animated without voice)
- Christopher Pike (Regular cast character for the second season of Star Trek: Discovery and Star Trek: Strange New Worlds.)
- ST:
- Spock (series regular in Star Trek: Strange New Worlds, Star Trek: The Animated Series and TOS films)
- TNG:
- Star Trek Generations (photograph)
- DS9: "Trials and Tribble-ations" (archive footage)
- Star Trek
- Star Trek Into Darkness
- Star Trek Beyond (photographs)
- DIS:
- "Brother"
- "Light and Shadows"
- "If Memory Serves"
- "Project Daedalus"
- "The Red Angel"
- "Perpetual Infinity"
- "Through the Valley of Shadows"
- "Such Sweet Sorrow"
- "Such Sweet Sorrow, Part 2"
- "Unification III" (archive footage)
- ST:
- LD: "No Small Parts" (photograph)
- PRO: "Kobayashi" (hologram)
- VST: (non-canon)
- "Skin a Cat"
- "Holiday Party"
- "Holograms All the Way Down" (hologram) (animated without voice)
- "Walk, Don't Run" (animated without voice)
- Leonard McCoy (series regular in Star Trek: The Animated Series and TOS films)
- TNG: "Encounter at Farpoint"
- Star Trek Generations (photograph)
- DS9: "Trials and Tribble-ations" (archive footage)
- Star Trek Beyond (photograph)
- ST: "Ephraim and Dot" (animated without voice)
- VST: "Walk, Don't Run" (non-canon) (animated without voice)
- Montgomery Scott (series regular in Star Trek: The Animated Series and TOS films)
- TNG: "Relics"
- Star Trek Generations
- DS9: "Trials and Tribble-ations" (archive footage)
- Star Trek Beyond (photograph)
- PRO: "Kobayashi" (hologram)
- SNW:
- "A Quality of Mercy" (alternate reality)
- "Hegemony"
- VST: (non-canon)
- "Skin a Cat" (animated without voice)
- "Walk, Don't Run"
- Hikaru Sulu (series regular in Star Trek: The Animated Series and TOS films)
- Star Trek Generations (photograph)
- VOY: "Flashback"
- Star Trek Beyond (photograph)
- ST: "Ephraim and Dot" (archive voice only)
- LD: "Crisis Point 2: Paradoxus" (hallucination)
- VST: (non-canon)
- "Holograms All the Way Down" (hologram)
- "Walk, Don't Run"
- Pavel Chekov (series regular in TOS films)
- Star Trek Generations
- DS9: "Trials and Tribble-ations" (archive footage)
- Star Trek Beyond (photograph)
- Nyota Uhura (series regular in Star Trek: Strange New Worlds, Star Trek: The Animated Series and TOS films)
- Star Trek Generations (photograph)
- DS9: "Trials and Tribble-ations" (archive footage)
- Star Trek Beyond (photograph)
- PRO: "Kobayashi" (hologram)
- VST: (non-canon)
- "Holiday Party"
- "Holograms All the Way Down" (hologram) (animated without voice)
- "Walk, Don't Run" (animated without voice)
- Christine Chapel (series regular in Star Trek: Strange New Worlds and Star Trek: The Animated Series)
- Star Trek: The Motion Picture
- Star Trek IV: The Voyage Home
- VST: (non-canon)
- "Holiday Party" (animated without voice)
- "Walk, Don't Run" (animated without voice)
- Janice Rand
- Alice
- Nilz Baris
- DS9: "Trials and Tribble-ations" (archive footage)
- Zefram Cochrane
- Star Trek: First Contact
- ENT:
- "Broken Bow"
- "In a Mirror, Darkly" (archive footage) (as mirror Zefram Cochrane)
- LD: "Grounded" (hologram)
- Arne Darvin
- DS9: "Trials and Tribble-ations" (as his older self and also in archive footage)
- Freeman
- DS9: "Trials and Tribble-ations" (archive footage)
- Galloway
- DS9: "Trials and Tribble-ations" (archive footage)
- David Garrovick
- PRO: "All the World's a Stage" (voice recording only)
- Amanda Grayson
- Phillip Green
- Guardian of Forever
- Hadley
- DS9: "Trials and Tribble-ations" (archive footage)
- Hansen Al-Salah
- SNW: "A Quality of Mercy" (prime and alternate reality)
- Cyrano Jones
- TAS: "More Tribbles, More Troubles"
- DS9: "Trials and Tribble-ations" (archive footage)
- Kahless the Unforgettable
- TNG: "Rightful Heir" (as his clone)
- Kang
- DS9: "Blood Oath"
- VOY: "Flashback"
- George Samuel Kirk
- SNW:
- "Strange New Worlds"
- "Children of the Comet"
- "Lift Us Where Suffering Cannot Reach"
- "All Those Who Wander"
- "A Quality of Mercy" (alternate reality)
- "Charades"
- "Lost in Translation"
- "Subspace Rhapsody"
- "Hegemony"
- SNW:
- Koloth
- Kor
- Korax
- TAS: "More Tribbles, More Troubles"
- DS9: "Trials and Tribble-ations" (archive footage)
- Kyle
- Landru
- LD: "No Small Parts"
- Leslie
- DS9: "Trials and Tribble-ations" (archive footage)
- Abraham Lincoln (Excalbian)
- ST: "Ephraim and Dot" (animated without voice)
- LD: "Kayshon, His Eyes Open" (skeletal remains)
- Lurry
- DS9: "Trials and Tribble-ations" (archive footage)
- Angela Martine
- SNW: "A Quality of Mercy" (alternate reality)
- Gary Mitchell
- LD: "Strange Energies" photograph
- Harry Mudd
- Romulan Commander
- SNW: "A Quality of Mercy" (alternate reality)
- Stella Mudd
- Sarek
- TAS: "Yesteryear"
- TNG:
- "Sarek"
- "Unification I"
- DIS:
- "The Vulcan Hello"
- "Battle at the Binary Stars"
- "Lethe"
- "The Wolf Inside" (archive footage)
- "The War Without, The War Within"
- "Will You Take My Hand?"
- "Brother"
- "Light and Shadows"
- "Such Sweet Sorrow"
- Khan Noonien Singh
- ST: "Ephraim and Dot" (archive voice only)
- SNW: "Tomorrow and Tomorrow and Tomorrow"
- Stonn
- Surak
- T'Pau
- T'Pring
- SNW:
- VST: "Holiday Party" (non-canon)
- Robert Tomlinson
- SNW: "A Quality of Mercy" (alternate reality)
- Una Chin-Riley (series regular in Star Trek: Strange New Worlds)
- DIS:
- ST:
- VST: "Holiday Party" (non-canon)
- Vina
- Bob Wesley
- White Rabbit
Star Trek: The Animated Series[]
- Arex
- LD: "An Embarrassment Of Dooplers" (two photographs)
- VST: (non-canon)
- "Skin a Cat" (animated without voice)
- "Walk, Don't Run"
- I-Chaya
- VST: "Walk, Don't Run" (non-canon)
- M'Ress
- LD: "An Embarrassment Of Dooplers" (photograph)
- VST: (non-canon)
- Spock Two
- LD: "Kayshon, His Eyes Open" (skeletal remains)
- VST: "Walk, Don't Run" (non-canon) (animated without voice)
- Robert April
The Original Series films[]
Star Trek: The Next Generation[]
- Jean-Luc Picard (Series regular for TNG films and Star Trek: Picard.)
- DS9: "Emissary"
- ENT: "These Are the Voyages..." (archive voice only)
- ST: "Children of Mars" (photograph)
- DIS: "Red Directive" (archive image)
- William T. Riker (Series regular for TNG films)
- VOY: "Death Wish"
- ENT: "These Are the Voyages..."
- PIC:
- LD:
- VST: (non-canon)
- "Worst Contact"
- "Holograms All the Way Down" (hologram)
- "Walk, Don't Run"
- Data (Series regular for TNG films)
- ENT: "These Are the Voyages..." (voice only)
- PIC:
- "Remembrance" (dreams only)
- "Broken Pieces" (vision and archive footage only)
- "Et in Arcadia Ego, Part 2" (simulation only)
- "The Bounty" (archive footage)
- "Surrender" (digital personality)
- Geordi La Forge (Series regular for TNG films)
- VOY: "Timeless" (alternate future)
- PIC:
- "The Bounty"
- "Dominion"
- "Surrender"
- "Võx"
- "The Last Generation"
- Deanna Troi (Series regular for TNG films)
- VOY:
- "Pathfinder"
- "Life Line"
- "Inside Man"
- ENT: "These Are the Voyages..."
- PIC:
- LD: "No Small Parts"
- VST: "Holograms All the Way Down" (hologram) (non-canon) (animated without voice)
- VOY:
- Worf (Series regular for TNG films and Star Trek: Deep Space Nine starting with the fourth season.)
- PIC:
- "Remembrance" (photograph)
- "Disengage"
- "Seventeen Seconds"
- "Imposters"
- "The Bounty"
- "Surrender"
- "Võx"
- "The Last Generation"
- PIC:
- Beverly Crusher (Series regular for TNG films)
- PRO:
- "Kobayashi" (hologram)
- "Last Flight of the Protostar, Part II"
- "Ouroboros, Part II"
- PIC:
- VST: "Worst Contact" (non-canon)
- PRO:
- Wesley Crusher
- Natasha Yar
- Joshua Albert
- Ancient humanoid
- DIS:
- "Red Directive" (archive image)
- "Mirrors" (archive image)
- DIS:
- Arridor
- VOY: "False Profits"
- Reginald Barclay
- Star Trek: First Contact
- VOY:
- "Projections" (holographic image)
- "Pathfinder"
- "Life Line"
- "Inside Man" (also as a hologram)
- "Author, Author"
- "Endgame"
- Morgan Bateson
- B'Etor
- DS9: "Past Prologue"
- Star Trek Generations
- LD: "Cupid's Errant Arrow" (photograph)
- Boothby
- VOY:
- "In the Flesh" (Species 8472)
- "The Fight" (in Chakotay's hallucination and a hologram)
- VOY:
- Leah Brahms
- LD: "Mining The Mind's Mines" (illusion)
- Rachel Garrett
- PIC:
- "The Next Generation" (statue)
- "Imposters" (statue)
- PIC:
- Sonya Gomez
- Gowron
- DS9:
- "The House of Quark"
- "The Way of the Warrior"
- "Broken Link"
- "Apocalypse Rising"
- "By Inferno's Light"
- "When It Rains..."
- "Tacking Into the Wind"
- "What You Leave Behind" (archive footage)
- DS9:
- Guinan
- Hugh
- Edward Jellico
- Kalita
- Kol
- VOY: "False Profits"
- Kurn
- DS9: "Sons of Mogh"
- Nicholas Locarno
- Locutus of Borg
- DS9: "Emissary" (also impersonated by a Prophet)
- Star Trek: First Contact (in Picard's nightmare and flashbacks)
- PIC: "The Impossible Box" (archive footage)
- Lore
- Lursa
- DS9: "Past Prologue"
- Star Trek Generations
- LD: "Cupid's Errant Arrow" (photograph)
- Bruce Maddox
- PIC:
- "Stardust City Rag"
- "The Impossible Box" (archive footage)
- "Et in Arcadia Ego, Part 1" (archive footage)
- PIC:
- James Moriarty
- PIC: "The Bounty"
- Alynna Nechayev
- DS9:
- "The Maquis, Part II"
- "The Search, Part II" (virtual)
- DS9:
- Neral
- Keiko O'Brien
- DS9:
- "A Man Alone"
- "If Wishes Were Horses"
- "In the Hands of the Prophets"
- "The Siege"
- "Cardassians"
- "Rivals"
- "Armageddon Game"
- "Whispers"
- "Tribunal"
- "The House of Quark"
- "Fascination"
- "Accession"
- "Hard Time"
- "Body Parts"
- "Looking for par'Mach in All the Wrong Places"
- "The Assignment"
- "The Begotten"
- "Time's Orphan"
- "What You Leave Behind"
- DS9:
- Miles O'Brien (Regular cast character for Star Trek: Deep Space Nine and crossed back over for the TNG finale.)
- TNG: "All Good Things..."
- LD: "Temporal Edict" (statue)
- Molly O'Brien
- Alyssa Ogawa
- Thadiun Okona
- LD: "An Embarrassment Of Dooplers" (no lines)
- PRO:
- Q
- DS9: "Q-Less"
- VOY:
- "Death Wish"
- "The Q and the Grey"
- "Q2"
- LD: "Veritas"
- PIC:
- "The Star Gazer"
- "Penance"
- "Assimilation"
- "Watcher"
- "Fly Me to the Moon"
- "Two of One" (flashback; archive footage)
- "Mercy"
- "Farewell"
- "The Last Generation"
- Thomas Riker
- Ro Laren
- Alexander Rozhenko
- DS9:
- "The Way of the Warrior" (picture only)
- "Sons and Daughters"
- "You Are Cordially Invited"
- DS9:
- Elizabeth Shelby
- LD: "An Embarrassment Of Dooplers" (no lines)
- PIC: "Võx"
- Sito Jaxa
- Lwaxana Troi
- DS9:
- "The Forsaken"
- "Fascination"
- "The Muse"
- DS9:
- Vash
- Vellek
- DIS: "Red Directive" (archive image)
The Next Generation films[]
- Borg Queen
- VOY:
- PIC:
- "The Impossible Box" (archive footage)
- "The Star Gazer"
- "Penance"
- "Assimilation"
- "Watcher"
- "Fly Me to the Moon"
- "Two of One" (illusion)
- "Võx"
- "The Last Generation"
- LD: "I, Excretus" (hologram)
- Admiral Hayes
- VOY:
- "Hunters"
- "Hope and Fear"
- "Life Line"
- VOY:
- B-4
- PIC: "Remembrance" (remains only)
Star Trek: Deep Space Nine[]
- Kira Nerys
- Julian Bashir
- Quark
- TNG: "Firstborn"
- VOY: "Caretaker"
- Star Trek: Insurrection (scenes cut)
- LD: "Hear All, Trust Nothing"
- VST: (non-canon)
- "Holograms All the Way Down" (hologram)
- "Walk, Don't Run" (hologram) (animated without voice)
- Odo
- PRO: "Kobayashi" (hologram)
- PIC: "No Win Scenario" (photograph)
- Broik
- Chekote
- Evek
- Elim Garak
- VST: "Holograms All the Way Down" (hologram) (non-canon) (animated without voice)
- Falow
- LD: "Reflections"
- Leeta
- Martok
- LD: "The Least Dangerous Game" (program)
- Morn
- Rom
Miles O'Brien was a recurring character on TNG before becoming a regular cast character on DS9 and crossing back over for the TNG finale "All Good Things...".
Star Trek: Voyager[]
- Kathryn Janeway
- Star Trek Nemesis
- PRO:
- "A Moral Star, Part 2"
- "Asylum"
- "Let Sleeping Borg Lie"
- "All the World's a Stage"
- "Crossroads"
- "Masquerade"
- "Preludes"
- "Mindwalk"
- "Supernova, Part 1"
- "Supernova, Part 2"
- "Into the Breach, Part I"
- "Into the Breach, Part II"
- "Who Saves the Saviors"
- "Temporal Mechanics 101"
- "Observer's Paradox"
- "Imposter Syndrome"
- "The Fast and the Curious"
- "Is There in Beauty No Truth?"
- "The Devourer of All Things, Part I"
- "The Devourer of All Things, Part II"
- "Last Flight of the Protostar, Part II"
- "A Tribble Called Quest"
- "Cracked Mirror"
- "Ascension, Part I"
- "Ascension, Part II"
- "Brink"
- "Touch of Grey"
- "Ouroboros, Part I"
- "Ouroboros, Part II"
- Chakotay
- PRO:
- "Kobayashi" (holographic recording)
- "First Con-tact" (holographic recording)
- "Time Amok" (voice mimicked by Dred 2)
- "Asylum" (holographic recording)
- "Preludes"
- "Mindwalk"
- "Supernova, Part 2" (voice recording)
- "Into the Breach, Part I" (recording)
- "Who Saves the Saviors"
- "Observer's Paradox" (recording)
- "The Devourer of All Things, Part II" (no lines)
- "Last Flight of the Protostar, Part I"
- "Last Flight of the Protostar, Part II"
- "A Tribble Called Quest"
- "Cracked Mirror"
- "Ascension, Part I"
- "Ascension, Part II"
- "Brink"
- "Touch of Grey"
- "Ouroboros, Part I"
- "Ouroboros, Part II"
- PRO:
- The Doctor
- PRO:
- "Into the Breach, Part I"
- "Into the Breach, Part II"
- "Who Saves the Saviors"
- "Temporal Mechanics 101"
- "Observer's Paradox"
- "Imposter Syndrome"
- "The Fast and the Curious"
- "Is There in Beauty No Truth?"
- "The Devourer of All Things, Part I"
- "The Devourer of All Things, Part II"
- "Last Flight of the Protostar, Part II"
- "A Tribble Called Quest"
- "Cracked Mirror"
- "Ascension, Part I"
- "Ascension, Part II"
- "Brink"
- "Touch of Grey"
- "Ouroboros, Part I"
- "Ouroboros, Part II"
- PRO:
- Tom Paris
- Seven of Nine (series regular in Star Trek: Picard beginning with Season 2)
- Tuvok
- DS9: "Through the Looking Glass" (as mirror Tuvok)
- LD: "Grounded"
- PIC:
- "Dominion" (as Changeling Tuvok)
- "The Last Generation"
- Doctor Chaotica
- The Clown
- Icheb
- Michael Sullivan
- Lewis Zimmerman
- EMH
- DS9: "Doctor Bashir, I Presume" (as Deep Space 9 EMH)
- Star Trek: First Contact (as USS Enterprise-E EMH)
- Neelix
- VST: "Holograms All the Way Down" (hologram) (non-canon)
Star Trek: Enterprise[]
- Charles Tucker III
- VST: "Holograms All the Way Down" (hologram) (non-canon)
- Malcolm Reed
- VST: "Holograms All the Way Down" (hologram) (non-canon) (animated without voice)
- LD: "Empathological Fallacies" (picture on jigsaw puzzle and box)
- T'Pol
- VST: "Holograms All the Way Down" (hologram) (non-canon) (animated without voice)
- Travis Mayweather
- VST: "Holograms All the Way Down" (hologram) (non-canon) (animated without voice)
- Daniels
Star Trek: Discovery[]
- Michael Burnham
- ST: "The Girl Who Made the Stars"
- SNW: "Memento Mori" (archive voice only)
- Mike Burnham
- Saru
- ST: "The Brightest Star"
- VST: (non-canon)
- "Holiday Party"
- "Holograms All the Way Down" (hologram)
- "Walk, Don't Run" (animated without voice)
- Sylvia Tilly
- Philippa Georgiou
- ST: "The Brightest Star"
- VST: (non-canon)
- "Holiday Party" (animated without voice)
- "Walk, Don't Run" (animated without voice)
- Amin
- Upjohn
Short Treks[]
Star Trek: Picard[]
Star Trek: Lower Decks[]
- Barnes
- VST: "Walk, Don't Run" (hologram) (non-canon) (animated without voice)
- Beckett Mariner
- SNW: "Those Old Scientists"
- VST: (non-canon)
- "Holograms All the Way Down" (hologram) (animated without voice)
- "Walk, Don't Run" (animated without voice)
- Brad Boimler
- SNW: "Those Old Scientists"
- VST: (non-canon)
- "Holograms All the Way Down" (hologram) (animated without voice)
- "Walk, Don't Run" (animated without voice)
- Jennifer Sh'reyan
- VST: "Walk, Don't Run" (hologram) (non-canon) (animated without voice)
- Merp
- VST: "Walk, Don't Run" (non-canon) (animated without voice)
- Sam Rutherford
- D'Vana Tendi
- SNW: "Those Old Scientists"
- VST: (non-canon)
- "Holograms All the Way Down" (hologram)
- "Walk, Don't Run"
- Jack Ransom
- T'Ana
- VST: "Walk, Don't Run" (hologram) (non-canon) (animated without voice)
Star Trek: Strange New Worlds[]
- Hemmer
- VST: (non-canon)
- "Holiday Party"
- "Holograms All the Way Down" (hologram)
- VST: (non-canon)
Star Trek: Prodigy[]
- Gwyndala
- VST: "Holograms All the Way Down" (hologram) (non-canon) (animated without voice)
- Zero
- VST: "Holograms All the Way Down" (hologram) (non-canon)
- Rok-Tahk
- VST: "Holograms All the Way Down" (hologram) (non-canon) (animated without voice)
Historical[]
- Leonardo da Vinci
- TOS: "Requiem for Methuselah" (as Flint)
- VOY:
- "Scorpion" (hologram)
- "Concerning Flight" (hologram)
- LD: "Crisis Point" (hologram)
- Isaac Newton
- TNG: "Descent" (Isaac Newton hologram)
- VOY: "Death Wish"
Note[]
- No characters who first appeared in the alternate reality films have recurred in a subsequent series or film.