List of Star Trek characters
This article lists characters in the various canonical incarnations of Star Trek. This includes fictional major characters and fictional minor characters created for Star Trek, fictional characters not originally created for Star Trek, and real-life persons appearing in a fictional manner, such as holodeck recreations.
Main characters by series:
- Original Series
- Star Trek: The Next Generation
- Star Trek: Deep Space Nine
- Star Trek: Voyager
- Star Trek: Enterprise
- Captain Christopher Pike played by Jeffrey Hunter
- Mr. Spock, played by Leonard Nimoy
- Number One (unnamed character), played by Majel Barrett
- Yeoman Julie Margareth Colt, played by Laurel Goodwin
Regular crew of the USS Enterprise NCC-1701
- Captain James Tiberius Kirk, played by William Shatner
- Mr. Spock, played by Leonard Nimoy
- Doctor Leonard H. "Bones" McCoy, played by DeForest Kelley
- Lieutenant Uhura, played by Nichelle Nichols
- Chief Engineer Montgomery "Scotty" Scott, played by James Doohan
- Lieutenant Hikaru Sulu, played by George Takei
- Yeoman Janice Rand, played by Grace Lee Whitney (1966-1967)
- Ensign Pavel Chekov, played by Walter Koenig (1967-1969)
Other important characters
Star Trek: The Next Generation
- Captain Jean-Luc Picard, played by Patrick Stewart
- Commander William Thomas Riker, played by Jonathan Frakes
- Chief Engineer Geordi La Forge, played by LeVar Burton
- Lieutenant Natasha Yar, played by Denise Crosby (1987-1988)
- Lieutenant Commander Worf, played by Michael Dorn
- Chief Medical Officer Beverly Crusher, played by Gates McFadden (1987-1988; 1989-1994)
- Counsellor/Lieutenant Commander/Commander Deanna Troi, played by Marina Sirtis
- Lieutenant Commander Data, played by Brent Spiner
- Guinan, played by Whoopi Goldberg (1988-1993)
- Transporter Chief Miles Edward O'Brien, played by Colm Meaney
- Chief Medical Officer Katherine Pulaski, played by Diana Muldaur (1988-1989)
- Acting Ensign Wesley Crusher
Other important characters
- Lieutenant Reginald Barclay
- Ensign/Lieutenant Ro Laren
- Spot (Data's pet cat)
- Lwaxana Troi, Daughter of the Fifth House, Holder of the Sacred Chalice of Rixx, Heir to the Holy Rings of Betazed
Star Trek: Deep Space Nine
- Commander/Captain Benjamin Lafayette Sisko, played by Avery Brooks
- Constable Odo, played by Rene Auberjonois
- Chief Medical Officer Julian Bashir, played by Alexander Siddig
- Lieutenant/Lieutenant Commander Jadzia Dax, played by Terry Farrell
- Major/Colonel Kira Nerys, played by Nana Visitor
- Lieutenant Commander Worf, played by Michael Dorn
- Lieutenant j.g. Ezri Dax, played by Nicole deBoer
- Rom, played by Max Grodénchik
- Elim Garak, played by Andrew Robinson
- Morn, played by Mark Allen Shepherd
- Ensign Nog, played by Aron Eisenberg
- Jake Sisko, played by Cirroc Lofton
- Quark, played by Armin Shimerman
- Chief of Operations Miles Edward O'Brien, played by Colm Meaney
Other important characters
- Kasidy Yates
- Admiral Ross
- Grand Nagus Zek
- Kai Winn
- Vedek Bareil
- Keiko O'Brien
- Female Shapeshifter
Star Trek: Voyager
- Captain Kathryn Janeway, played by Kate Mulgrew
- Lieutenant Thomas Eugene Paris, played by Robert Duncan McNeill
- Ensign Harry Kim, played by Garrett Wang
- The Holographic Doctor (EMH Program Mark-1), played by Robert Picardo
- Kes, played by Jennifer Lien
- Neelix, played by Ethan Phillips
- Commander Chakotay, played by Robert Beltran
- Lieutenant Commander Tuvok, played by Tim Russ
- Chief Engineer B'Elanna Torres, played by Roxann Dawson
- Seven of Nine, played by Jeri Ryan
Other important characters
- Lieutenant Reginald Barclay, played by Dwight Schultz
- Naomi Wildman, played by Scarlett Pomers
- Seska, played by Martha Hackett.
Star Trek: Enterprise
- Captain Jonathan Archer, played by Scott Bakula
- Commander Charles "Trip" Tucker III, played by Connor Trinneer
- Ensign Travis Mayweather, played by Anthony Montgomery
- Sub-commander T'Pol, played by Jolene Blalock
- Doctor Phlox, played by John Billingsley
- Porthos (Captain Archer's pet beagle)
- Lieutenant Malcolm Reed, played by Dominic Keating
- Ensign Hoshi Sato, played by Linda Park
Characters from all series, listed alphabetically
|No pic||Leonard James Akaar||Friday's Child (TOS)|
|Male; son of Akaar and Eleen, named after James T. Kirk and Leonard McCoy after they helped out the inhabitants of Capella IV. In the novels, Akaar grows up and joins Starfleet; we first see him serving as chief of security on the USS Excelsior under Captain Hikaru Sulu. Later, in the Star Trek: Deep Space Nine relaunch novels, Akaar is a veteran admiral in the fleet.|
|No pic||Akorem Laan||Accession (DS9)|
|Bajoran male; poet best known for The Call of the Prophets. Traveling in a Bajoran lightship, he was the first to find the Celestial Temple (the wormhole to the Gamma Quadrant) and when he emerged about 200 years later Sisko gave up his title of Emissary so that Akorem could take it, a decision Sisko regretted when Akorem advocated a return to the D'Jarras (the Bajoran caste system). Sisko and Akorem went to the wormhole together and the Prophets decided to send Akorem back to his time and reinstate Sisko as their Emissary.|
|No pic||Alixus||Paradise (DS9)|
|Female; stranded colonizers on Orellius to establish a society free of technology.|
|No pic||Altovar||Distant Voices (DS9)|
|Lethean male; attempted to buy biomimetic gel from Dr. Bashir. Telepathically attacked him when he refused to sell.|
|No pic||Aluura||Profit and Lace (DS9)|
|Female; A dabo girl at Quark's, admired by all her clients and colleagues. Quark threatened to fire her if she did not give him oo-mox.|
|No pic||Kiaphet Amman'sor||None|
|Female Xindi-aquatic; member of the Ibix dynasty, and the head aquatic in the Xindi Council. She is always seen in a tank that adjoins the Council chamber.|
|No pic||Anya||The Dauphin (TNG)|
|Female allasomorph; shapeshifter from the third moon of Daled IV.|
|Not seen on screen||Robert April||None||None|
|Human male; former captain of USS Enterprise NCC-1701.|
|No pic||Ardra||Devil's Due (TNG)|
|Devil of Ventrax II, impersonated by a conwoman, only to be revealed as a hoax by Captain Picard.|
|100px||Armus||None||Skin of Evil (TNG)|
|Sentient oil slick that killed Tasha Yar.|
|No pic||Dr. Arridor||The Price (TNG)|
|Ferengi male; one of two Ferengi stranded in the Delta Quadrant after attempting to secure the Barzan wormhole for themselves. Crash-landing on the Takaran homeworld, they insinuated themselves to be the Holy Sages prophesied by the Takaran Song of the Sages in order to exploit the Takarans for profit.|
|100px||Jeremy Aster||The Bonding (TNG)|
|Human male; lost his mother to a mission Worf commanded; through a Klingon ritual became a brother of Worf.|
|Klingon female; apparently, the only Klingon female to be Chancellor of the High Council.|
- B-4, prototype for Data
- Bahrat (VOY, "Fair Trade") Manager of the Nekrit Supply Depot, near the Nekrit Expanse
- Ensign Lyndsay Ballard (VOY, "Ashes to Ashes") Engineer, died in an away mission she went on with Harry Kim. She was buried "in space" and found by the Kobali, who "procreate" by reanimating alien corpses and altering their physiology to match theirs. She was renamed Jhet'laya, and after living with her Kobali family for two years, she escaped and got back to Voyager, where the Doctor performed cosmetic surgery to make her look more human. When other Kobali came looking for her, she at length decided to return to them.
- Barash (TNG, "Future Imperfect") Lonely child who trapped Riker in a fictitious future
- Reginald Barclay, played by Dwight Schultz from The A-Team
- Professor Honey Bare (DS9, "Our Man Bashir") A seismologist in Bashir's secret agent program. Due to a transporter malfunction, Prof. Bare's physical parameters were temporarily modelled on Jadzia Dax.
- Vedek Bareil (DS9) Was nominated as possible successor to Kai Opaka, but lost the position to Winn instead
- Amsha Bashir (DS9, "Doctor Bashir, I Presume?") Wife of Richard Bashir, mother of Julian Bashir. Played by Fadwa El Guindi.
- Julian Bashir, Chief Medical Officer of DS9
- Richard Bashir (DS9, "Doctor Bashir, I Presume?") Husband of Amsha Bashir, father of Julian Bashir. Played by Brian George. In 2348, he took his then 6-year-old son to a planet outside the Federation to have him genetically enhanced. When the fact came out in the open about three decades later, Richard accepted a 2-year prison sentence to save Julian's career.
- Captain Morgan Bateson (TNG, "Cause and Effect"), played by Kelsey Grammer, commanded the USS Bozeman, which was trapped in a time loop for 80 years
- Singh el Bashir (DS9, "Statistical Probabilities") 15th Century poet and plagiarist, ancestor of Julian Bashir.
- Belle (VOY, "Real Life") The Doctor's daughter in his holographic family program.
- B'Etor, one of the Duras sisters
- Gabriel Bell (DS9, "Past Tense") (April 24, 1987 - September 3, 2024) During a 2024 revolt in San Francisco where federal employees were held hostage, he made sure the hostages were not harmed. In an alternate timeline, Bell was killed earlier and Benjamin Sisko stepped in to fulfill Bell's role in the pivotal historical moment. In a guidebook to Earth that Jake gave to Nog, Gabriel Bell is described as "the father of Earth's post-modern reformism," and shown with a picture of Sisko.
- Benaren Father of Kes, husband of Martis. Played by Michael L. Maguire.
- DaiMon Bok (TNG, "The Battle") Tried to wreak vengeance on Picard for the Battle of Maxia
- Leah Brahms, Engineer who developed the Warp drive of Galaxy class starships, first appeared as a hologram in an Enterprise tutorial, later in person as a romantic interest of Geordi La Forge.
- Admiral Brand
- Captain Braxton 29th century time traveller stranded in 20th century Los Angeles for 30 years
- Liquidator Brunt (DS9), Ferengi who works for the Ferengi Commerce Authority.
- Butler, Kirk's dog
- Lord Byron (VOY, "Darkling") Holographic recreation of 19th Century poet. Voyager 's EMH attempted to incorporate some of the poet's traits into his own program.
|No pic||Charlene||Real Life (VOY)|
|Hologram; the Doctor's wife in his holographic family program.|
|No pic||Ch'Pok||Rules of Engagement (DS9)|
|Klingon male; lawyer arguing for Worf's extradition to the Klingon Empire for allegedly killing 441 Klingon civilians.|
|No pic||Sonny Clemonds||The Neutral Zone (TNG)|
|Human male; 20th Century civilian cryogenically frozen and discovered by the USS Enterprise-D.|
|100px||Zefram Cochrane||Glenn Corbett; James Cromwell||Metamorphosis (TOS)|
|Human male; Earth's inventor of warp drive.|
|No pic||Jack Crusher||Family (TNG)|
|Human male; husband of Beverly Crusher; father of Wesley Crusher.|
|100px||Crystalline Entity||None||Datalore (TNG)|
|Seemingly malevolent life form that destroyed colonies on Omicron Theta and other planets.|
- Dammar (VOY, "Displaced") The first Nyrian pretending to have been posited on Voyager without his consent.
- Gul Darhe'el called "The Butcher of Gallitep" for his role in the Cardassian occupation of Bajor
- Dathon (TNG, "Darmok")
- Carmen Davila Colonizer who died in a Chrystalline Entity attack
- Dax symbiont Trill worm, over 300 years old
- Audrid Dax Fourth host of Dax symbiont
- Curzon Dax Host of Dax symbiont before Jadzia
- Emony Dax Third host of Dax symbiont
- Ezri Dax Host of Dax symbiont after Jadzia
- Jadzia Dax Host of Dax symbiont after Curzon
- Joran Dax Sixth host of Dax symbiont
- Lela Dax First host of Dax symbiont
- Tobin Dax Second host of Dax symbiont
- Torias Dax Fifth host of Dax symbiont
- Yedrin Dax (DS9, "Children of Time") Descendant of Jadzia Dax and host of the Dax symbiont in an alternate timeline
- Richard Daystrom (TOS, "The Ultimate Computer"), creator of M5 multitronic computer system.
- Willard Decker (ST:TMP), Captain of the Enterprise NCC-1701 before leaving to become V'ger's human representative.
- Degra (ENT, third season), Xindi scientist who supervised construction of the Xindi weapon.
- DeSeve (TNG, "Face of the Enemy") Starfleet officer who defected to Romulus.
- Klim Dokachin (TNG, "Unification II"), Zakdorn quartermaster and administrator of the Federation Surplus Depot Z15.
- Dolim Also known as Guruk, military officer who hijacked the Xindi weapon (ENT, third season)
- Jenna D'Sora (TNG, "In Theory"), crewwoman who fell in love with Data.
- Duchamps (DS9, "Our Man Bashir") An assistant to Dr. Noah in Bashir's secret agent program. Due to a transporter malfunction, Duchamps's physical parameters were temporarily modelled on Worf.
- Duras, notably aggressive and dishonest dynasty of the Klingon empire.
|No pic||Amelia Earhart||The 37s (VOY)|
|Human female; abducted from Earth in 1937; found cryogenically frozen in the Delta Quadrant by the Voyager crew.|
|No pic||Michael Eddington|
|Human male; lieutenant commander; Starfleet security officer who defected to join the Maquis.|
|No pic||Ee'Char||Hard Time (DS9)|
|Male; Miles O'Brien's imaginary cellmate during his time-compressed simulation of incarceration.|
|No pic||Albert Einstein||Descent, Part I (TNG) |
The Nth Degree (TNG)
|Holographic reproduction for a game of poker with Data|
|No pic||Ekoria||The Quickening (TNG)|
|Teplan female; afflicted by the blight, the first one to believe that Bashir could find a cure to her condition. She died to the blight, but her baby was born perfectly healthy.|
|No pic||Elaan of Troyius||Elaan of Troyius (TOS)|
|Female; princess offered in marriage to resolve conflict between two worlds.|
|No pic||Tam Elbrun||Tin Man (TNG)|
|Betazoid male; had unusually great telepathic ability skilled at making contact with non-humanoid sentient life forms.|
|No pic||Endar||Suddenly Human (TNG)|
|Talarian male; captain whose own biological son was killed by humans. In accordance with Talarian customs, he claimed the human boy Jeremiah Rossa as his own son, renaming him Jono. Years later, when Captain Picard intended to return Jono to his human family, Endar was ready to go to war to retrieve his adopted son.|
|No pic||Kivas Fajo||The Most Toys (TNG)|
|Male; kidnapped Data for his collection of priceless artifacts.|
|No pic||Falcon||Our Man Bashir (DS9)|
|Hologram; assassin in Bashir's secret agent holo-program. Due to a transporter malfunction, Falcon's physical parameters were temporarily modelled on O'Brien.|
|No pic||Dr. Farek||Menage a Troi (TNG)|
|Ferengi male; crew member of the Krayton, tried using a mind probe on Lwaxana Troi to learn the secret of Betazed telepathy.|
|No pic||Karen Farris||Courtney Peldon||Valiant (DS9)|
|Human female; Red Squad cadet appointed First Officer of the USS Valiant after the death of Captain Ramirez.|
|No pic||Marla Finn|
|No pic||Vic Fontaine|
|Hologram; a holodeck entertainer, used as counselor by various crewmembers of Deep Space Nine.|
- Richard Galen Renowned anthropologist and role model for Picard
- Mahatma Gandhi (VOY, "Darkling") Holographic recreation of 20th Century politician. Voyager 's EMH attempted to incorporate some of Gandhi's traits into his own program.
- Garak, a "plain and simple tailor", in reality a former top operative of the Obsidian Order.
- Garth of Izar: Hero of the Battle of Axanar and role model for Captain James T. Kirk
- Gegen (VOY, "Distant Origin") Saurian scientist who believes his Delta Quadrant race are descendants of Earth dinosaurs.
- Tekeny Ghemor (DS9, "Second Skin", "Ties of Blood and Water") Father of a Cardassian young woman who went undercover as a Bajoran. As a young man, Ghemor played a role in the Kiessa massacre. After an attempt to pass Kira as his long lost daughter fails, Ghemor grows close to Kira and considers her the closest thing to family, so much so that he asked her to participate in the Cardassian ritual of shri-tal before he died of Yurim Fel syndrome.
- Sonya Gomez (TNG, "Q Who?"), young Starfleet ensign serving on the Enterprise in the engineering section, famously spilt Hot Chocolate on Captain Picard. She has a considerably larger role in the S.C.E. novels.
- Chancellor Gorkon (TUC) Chancellor of the Klingon Empire
- Chancellor Gowron (TNG and DS9) Chancellor of the Klingon Empire
- Amanda Grayson (TOS, "Journey to Babel"), the human mother of Mr. Spock.
- Greskrendregtk (VOY, -never seen-), the Ktarian father of Naomi Wildman
- Grilka (DS9, "House of Quark") Briefly married to Quark after Quark was implicated in the murder of her previous husband, Kozak
- G'Trok Klingon poet best known for the epic "The Fall of Kang"
- Guruk Xindi military officer
- Annika Hansen, Seven of Nine's designation before assimilation.
- Erin Hansen Wife of Magnus Hansen, mother of Annika Hansen. Studied the Borg up close.
- Magnus Hansen Husband of Erin Hansen, father of Annika Hansen. Studied the Borg up close.
- Captain John Harriman (TOS), captain of the USS Enterprise-B on its maiden voyage in 2293.
- Stephen Hawking (TNG, "Descent, Part I") Holographic reproduction for a game of poker with Data. Played by the real Stephen Hawking.
- Dixon Hill, played by Jean-Luc Picard on the holodeck
- Sherlock Holmes, character created by Arthur Conan Doyle, played by Data on the holodeck
- Mr. Homn, valet to Lwaxana Troi, mother of Deanna Troi.
- Hugh, 3 of 5
- Mark Jameson (TNG, "Too Short a Season") Renowned Federation mediator who tried an unorthodox age-reversal treatment
- Jarlath (VOY, "Displaced") Captive on a habitat customized by the Nyrians. He discovered passages between habitats.
- Captain Edward Jellico (TNG, "Chain of Command"), acting captain of the Enterprise-D while Jean-Luc Picard was engaged in negotiations with the Cardassians.
- Jeffrey (VOY, "Real Life") The Doctor's son in his holographic family program.
- Ma'Bor Jetrel (VOY, "Jetrel") Repented for engineering weapon that killed millions of Talaxians
- Jeyal (DS9, "The Muse") Tavnian, briefly Lwaxana Troi's husband and father of one of her children. When he learned the unborn child was a male, he insisted that upon birth he be separated from his mother and raised only by men in accordance with Tavnian tradition.
- Jono (TNG, "Suddenly Human") Human born Jeremiah Rossa, adopted by Talarian Captain Endar in accordance with Talarian customs. When found by the Enterprise-D, Picard wanted to return him to his biological grandmother, Admiral Conaught Rossa, but Jono, who had then reached the Age of Decision, decided to return to Endar.
- Kahless Legendary Klingon warrior and first emperor of the Klingon Empire; a clone created in 2369 was made ceremonial emperor by Gowron
- Kamala (TNG, "The Perfect Mate")
- Kang (TOS, DS9, VOY) Klingon captain who fought alongside Kirk against an empathic entity, later swore a blood vow with Dax to avenge his son's death at the hands of the Albino, played by Michael Ansara
- Walker Keel (TNG, "Conspiracy") Starfleet Commander who warned Picard about alien invasion.
- Edith Keeler (TOS, "City on the Edge of Forever") Charitable woman whose untimely demise turned out to be necessary to prevent Hitler from winning World War II, played by Joan Collins
- K'Ehleyr (TNG, "The Emissary"), wife of Worf, mother of Alexander Rozhenko, played by Suzie Plakson
- Captain Keogh (DS9, "The Jem-Hadar"), commander of the ill-fated USS Odyssey
- Lenara Khan (DS9, "Rejoined") Trill woman hosting the Khan symbiont, who in a former life was married to Dax, played by Susanna Thompson
- Kira Meru (DS9, "Wrongs Darker than Death or Night") Mother of Kira Nerys, was a comfort woman for Gul Dukat for seven years.
- Kira Nerys (DS9) Bajoran militia officer assigned as Benjamin Sisko's second in command on Deep Space Nine, played by Nana Visitor
- K'Kath (VOY, "Real Life") Klingon friend of Jeffrey in the holographic family program modified by Torres.
- Klag (TNG, "A Matter of Honor") Second officer of the Klingon bird-of-prey Pagh.
- K'mtar (TNG, "Firstborn") The adult Alexander Rozhenko from a possible future, played by James Sloyan
- Kodos the Executioner aka Anton Karidian (TOS, "The Conscience of the King") Governor of Tarsus IV, who engaged in a large-scale eugenics programme to counter impending threat of starvation to the colony, later assumed the role of an actor leading a traveling Shakespeare company
- Kol (TNG, "The Price"; VOY, "False Profits") One of two Ferengi stranded in the Delta Quadrant after attempting to secure the Barzan wormhole for themselves. Crash-landing on the Takaran homeworld, they insinuated themselves to be the Holy Sages prophesied by the Takaran "Song of the Sages" in order to exploit the Takarans for profit.
- Anastasia Komononov (DS9, "Our Man Bashir") A Russian spy in Bashir's secret agent program. Due to a transporter malfunction, Komononov's physical parameters were temporarily modelled on Kira.
- Sirma Kolrami (TNG, "Peak Performance") War strategy consultant for war games between the Enterprise-D and the Hathaway
- Kolopak, father of Chakotay
- Korenna (VOY, "Remember") Enaran woman in a star-crossed romance with a primitive regressive. She eventually passed on the memories of the genocide of the regressives to B'Elanna Torres.
- Kozak Klingon who accidentally died at Quark's bar. The financial assets of his House were being siphoned off by the Duras family by using Ferengi-like tactics.
- Kurn (TNG, DS9) Son of Mogh, brother of Worf, played by Tony Todd
- Silva La Forge, mother of Geordi La Forge
- Lal, daughter of Data
- Natima Lang, a Cardassian radical, the love of Quark's life (DS9, "Profit and Loss")
- Larg (VOY, "Real Life") Klingon friend of Jeffrey in the holographic family program modified by Torres.
- Sam Lavelle (TNG, "Lower Decks") Junior officer aboard the Enterprise-D
- Robin Lefler (TNG, "The Game") Ensign (engineering section) and friend of Wesley Crusher
- Janice Lester (TOS, "Turnabout Intruder") Former lover of Kirk's, temporarily swapped bodies with him
- Li Nalas (DS9, "The Homecoming") Bajoran resistance fighter who became a hero of mythological proportions after unwittingly killing a Cardassian
- Linnis (VOY, "Before And After") Daughter of Tom Paris and Kes, mother of Andrew, in an alternate timeline. Played by Jessica Collins.
- Nick Locarno Classmate of Wesley Crusher's at Starfleet Academy. Some fans believe he is the same person as Tom Paris
- Locutus a drone within the Borg Collective made using the body of Captain Picard
- Lore, "evil brother" of Data
- Colonel Lovok Romulan Tal Shiar officer replaced by a changeling in order to lead the Romulans into a Jem'haddar ambush
- Philippa Louvois Starfleet Judge Advocate General
- Lumba (DS9, "Profit and Lace") Quark's alias while a temporary Ferengi female.
- Lursa, one of the Duras sisters
- Keiran MacDuff (TNG, "Conundrum") Satarran operative who infiltrated the Enterprise-D after a mass amnesia incident
- Marayna (VOY, "Alter Ego") Operator of a station inside an inversion nebula. When Voyager passed by, she created a human version of herself in Neelix's holographic resort program
- Dr. Kila Marr (TNG, "Silicon Avatar") Dr. Kila Marr is a xenologist dedicated to the study of the Crystalline Entity. After the entity destroyed all life on the Omicron Theta science colony, including her son, in 2338 she became obsessed. When the Enterprise-D encountered the entity in the episode Silicon Avatar in the year 2368 she shattered it with high intensity energy waves.
- Dr. Carol Marcus, inventor of the Genesis Device, mother of Kirk's only known son
- Aamin Marritza (DS9, "Duet") Impersonated Gul Darhe'el to atone for Cardassian war crimes
- Martis Mother of Kes, wife of Benaren. Played by Rachel Harris.
- Martus Mazur (DS9, "Rivals") El-Aurian who promoted gambling device that turned out to have strange effects on quantum probability
- Dr. M'Benga (TOS) Assistant to Dr. McCoy
- Marla McGivers Cohabitated with Khan
- Ki Mendrossen (TNG, "Sarek") Assistant to Ambassador Sarek for the Legaran negotiations
- Minuet, Riker's holodeck fantasy woman, created by the Bynars and reproduced by Barash
- Miri (TOS, "Miri")
- Mogh, father of Worf
- Moogie (DS9) Quark and Rom's mother
- Morn, regular to Quark's bar, but never talks
- James Moriarty, character created by Arthur Conan Doyle, becomes sentient in the holodeck
- Crell Moset (VGR, "Nothing Human") Cardassian doctor, cured the Fostossa virus by experimenting on Bajorans. When B'Elanna Torres was invaded by a cytoplasmic lifeform, the Voyager EMH was assisted by a holographic reproduction of Dr. Moset, and the procedure was a success. But because Maquis crewmembers objected to Dr. Moset, the EMH decided to delete the program.
- Mot Barber on Enterprise-D
- Harry Mudd (TOS), aka Harcourt Fenton Mudd
- Father Mulligan Alias used by The Doctor while in Fair Haven as a priest.
- Nagilum (TNG, "Where Silence Has Lease")
- Nakahn (VOY, "Darkling") Mikhal Traveller, owner of a lodge
- Neelix Barclay's pet cat, named after Voyager's Talaxian
- Sir Isaac Newton (TNG, "Descent, Part I") Holographic reproduction for a game of poker with Data
- Nidell (DS9, "Second Sight") with possible redirect
- Nilva (DS9, "Profit and Lace") Slug-O-Cola tycoon and commissioner of the Ferengi Commerce Authority.
- Dr. Noah (DS9, "Our Man Bashir") A mad scientist in Bashir's secret agent program. Due to a transporter malfunction, Dr. Noah's physical parameters were temporarily modelled on Sisko.
- Nog, son of Rom, nephew of Quark
- Noggra (DS9, "The Sons of Mogh") Old family friend of Worf who took Kurn into his family.
- Noss (VGR, "Gravity") Woman who survived in Class D planet within sinkhole for several years. Fell in love with Tuvok. Portrayed by Lori Petty.
- N'Vek (TNG, "Face of the Enemy") Romulan subcommander who helped deliver Romulan dissidents to the Enterprise.
- Keiko O'Brien, wife of Miles O'Brien
- Miles O'Brien, transporter chief on the Enterprise-D, Chief of Operations at DS9
- Molly O'Brien, daughter of Miles and Keiko O'Brien
- Katie O'Claire Alias used by Kathryn Janeway while in Fair Haven
- Odala (VOY, "Distant Origin") Saurian minister who refuses to believe Professor Gegen's distant origin theory of their race.
- Odan (TNG, "The Host"), a precedent for Trills disregarded on DS9
- Odo (DS9) changling security officer
- Ralph Offenhouse 20th Century human cryogenically frozen and discovered by the Enterprise-D
- Alyssa Ogawa, nurse aboard the Enterprise-D
- Thadiun Okona (TNG, "The Outrageous Okona") Captain of a small freighter
- Omet'iklan (DS9, "To The Death") Jem'haddar First who threatened to kill Sisko after completing a mission to kill renegade Jem'haddar soldiers.
- Onaya (DS9, "The Muse") Vampiric being who feeds on creative energy. She claims to have helped artists all over the quadrant, including Earth's William Butler Yeats.
- Kai Opaka
- Douglas Pabst (DS9, "Far Beyond the Stars"), Editor of a science-fiction magazine in the 1950s, similar to Odo in appearance. Appeared to Sisko in a vision.
- Miral Paris Daughter of Tom Paris and B'Elanna Torres
- Melora Pazlar (DS9, "Melora") Native of a low-gravity planet who served in Starfleet
- Senator Pardek Romulan official agreeable to the idea of reunification with Vulcan
- Perrin Widow of Sarek
- Maurice Picard (TNG, "Tapestry") Wine grower, father of Jean-Luc Picard.
- René Picard Jean-Luc's nephew
- Robert Picard (TNG, "Family") Jean-Luc's brother
- Walter Pierce
- Christopher Pike, Captain of the Enterprise NCC-1701 before James T. Kirk
- Vedek Porta (DS9, "Accession") Bajoran Vedek who killed a member of his group after he refused to follow his D'Jarra.
- Porthos, Archer's dog
- Prinadora, a Ferengi female. She was the former wife of Rom, and the mother of their son Nog. She took advantage of Rom's love for her and tricked him into signing an extension to their marriage contract; Prinadora's father was subsequently able to swindle Rom out of all his money, whereupon Prinadora left Rom for another man.
- Captain Proton, played by Tom Paris on the holodeck
- Q, various beings from the Q Continuum
- Qatai (VGR, "Bliss") Man who hunted large, spacefaring bioplasmic lifeform for at least 40 years.
- Dr. Dalen Quaice (TNG, Remember Me) Old colleague of Dr. Crusher's
- Quark, Ferengi bartender
- Gregory Quinn, infested by alien parasite conspiring against humanity
- Rakal (TNG, "Face of the Enemy") Romulan Tal Shiar officer. She was killed by dissidents who then drafted Troi to impersonate her.
- Berlinghoff Rasmussen (TNG, "A Matter of Time") Con artist who travelled forward in time with the intention of stealing technology from the future and then patenting it in his own time
- Claire Raymonds 20th Century human cryogenically frozen and discovered by the Enterprise-D
- Cyrus Redblock Fictional 1940s crime boss, from Picard's "Dixon Hill" holodeck adventures
- Dexter Remmick, infested by alien parasite conspiring against humanity
- Captain Paul Rice, warned Picard of a conspiracy at Starfleet Headquarters
- Kyle Riker (TNG, "The Icarus Factor"), civilian strategist, father of William Riker
- Thomas Riker, transporter clone of William Riker
- Rislan (VOY, "Displaced") Nyrian scientist pretending to help Torres with the unexplained transports switching the Voyager crew with Nyrians.
- Riva (TNG, "Loud as a Whisper")
- Captain Rixx (TNG, "Conspiracy") Captain of USS Thomas Paine, helped warn Picard about alien invasion.
- Ro Laren Served in Starfleet, later joined the Maquis
- Rain Robinson (VOY, "Future's End", Parts I & II) Young woman working for SETI
- Rodek (DS9, "The Sons of Mogh") Son of Noggra. Identity given to Kurn after Worf failed to fulfill Kurn's request for ritual murder.
- Amanda Rogers (TNG, "True Q") Raised as a human but actually a member of the Q Continuum
- Rom, brother of Quark
- Ronin (TNG, "Sub Rosa")
- Admiral Conaught Rossa Biological grandmother of Jeremiah Rossa.
- Jeremiah Rossa See Jono.
- Jackson Roy Kirk (TOS, "The Changeling"), 21st Century robotics engineer who built the space probe known as Nomad which was launched from Earth to explore the galaxy.
- Alexander Rozhenko, son of Worf
- Helen Rozhenko, adopted mother of Worf
- Nikolai Rozhenko (TNG, "Homeward Bound"), Worf's human adopted brother
- Sergey Rozhenoko, adopted father of Worf
- Benny Russell (DS9, "Far Beyond the Stars"), African-American science-fiction writer in the 1950s. The magazine he worked for refused to publish one of his stories featuring "a Negro captain". Appeared to Sisko in a vision.
- Saavik (Star Trek II; Star Trek III; Star Trek IV) Half-Vulcan, half-Romulan Starfleet officer, played first by Kirstie Alley, later by Robin Curtis
- Sakkath (TNG, "Sarek") assistant to Sarek during the Legaran negotiations
- Sarek Famed Vulcan ambassador and father of Spock, played by Mark Lenard
- Sarjenka (TNG, "Pen Pals") Native of a seismically active planet who was helped by Data, played by Nikki Cox
- Admiral Norah Satie (TNG, "The Drumhead") Legendary Starfleet admiral who headed a paranoia-fueled investigation aboard Enterprise-D, played by Jean Simmons
- Tryla Scott (TNG, "Conspiracy") Youngest Captain in Starfleet history, helped warn Picard of alien invasion
- Sela (TNG) Daughter of Tasha Yar and a Romulan officer
- Dr. Selar (TNG, "The Schizoid Man") Vulcan medical officer on Enterprise-D, played by Suzie Plakson
- Subcommander Selok (TNG, "Data's Day") with possible redirect or disambiguation from T'Pel
- Gideon Seyetik (DS9, "Second Sight") Arrogant terraformer, played by Richard Kiley
- Shakaar Edon (DS9) Former leader of Bajoran resistance during Cardassian occupation, later First Minister of Bajor, played by Duncan Regehr
- Shinzon (Star Trek: Nemesis) An imperfect clone of Picard who attempted to seize control of the Romulan Empire, played by Tom Hardy
- Jaglom Shrek (TNG, "Birthright, Part I") Yridian with information to sell about Klingons captured by Romulans at Khitomer.
- Khan Noonien Singh (TOS, "Space Seed"; Star Trek II) Genetically enhanced superman from the late 1990's who attempted to seize control of the Enterprise and later took revenge on Admiral Kirk, played by Ricardo Montalban
- Benjamin Sisko Station commander of DS9 and Emissary to the Prophets, played by Avery Brooks
- Jake Sisko (DS9) Son of Benjamin and Jennifer Sisko, played by Cirroc Lofton
- Jennifer Sisko (DS9) Wife of Benjamin Sisko, killed at Wolf 359, but survived in mirror universe, played by Felecia M. Bell
- Joseph Sisko (DS9) New Orleans restaurateur and father of Benjamin Sisko, played by Brock Peters
- Korenna Sisko (DS9, "The Visitor") Bajoran wife of Jake Sisko in an alternate future, played by Galyn Görg
- Sito Jaxa (TNG, "Lower Decks") Bajoran junior officer aboard the Enterprise-D, played by Shannon Fill
- Luther Sloan (DS9) Section 31 operative who attempted to recruit Bashir numerous times, played by William Sadler
- Lily Sloane (FCT) Twenty-first century human female who was treated for radiation poisoning on the Enterprise, and later befriended Captain Picard
- Sonak (The Motion Picture) Potential replacement for Mr. Spock, died in a transporter accident.
- Arik Soong (ENT, "Borderland") Criminal creator of genetically engineered humans, ancestor of Noonien Soong, played by Brent Spiner
- Noonien Soong (TNG) Human cyberneticist who created Data, played by Brent Spiner
- Tolian Soran (Star Trek: Generations) El-Aurian scientist desperate to return to the Nexus, played by Malcolm McDowell
- Sovak (TNG, "Captain's Holiday") Ferengi who sought to profit from an archeaological search for the Tox Uthat, played by Max Grodénchik
- Spot Data's pet cat
- Henry Starling (VOY, "Future's End", Parts I & II) 20th century pothead turned entrepreneur after discovering a 29th century spacecraft crash-landed near his campsite, played by Ed Begley, Jr.
- Stonn (TOS, "Amok Time") Vulcan, T'Pring's lover
- Dr. Paul Stubbs (TNG, "Evolution") Astrophysicist played by Ken Jenkins, who now plays Dr. Kelso on Scrubs
- Lon Suder (VOY) Bajoran Maquis psychopath who helped retake Voyager after it was commandeered by the Kazon, played by Brad Dourif
- Michael Sullivan (VOY) Holographic character in Tom Paris's Fair Haven, owner of a pub in a quaint Irish village. He became romantically involved with Captain Janeway, who made several modifications to his program, until she told the computer to not allow her to make any more modifications.
- Demora Sulu (Star Trek: Generations) Hikaru Sulu's daughter, served aboard the Enterprise-B, played by Jacqueline Kim
- Surak (TOS, "The Savage Curtain") Legendary Vulcan who led his people to a logical lifestyle
- Sutok (VOY, "Fair Trade") Drug addict who buys his drugs at the Nekrit Supply Depot
- Sybok (Star Trek V) Spock's half-brother, played by Laurence Luckinbill
- Syrran (ENT, "The Forge"), the founder of a Vulcan splinter group following the teachings of the philosopher Surak
- Enabran Tain (DS9), Cardassian master spy, father of Garak, and head of the Obsidian Order. Played by Paul Dooley.
- Juliana Tainer (TNG, "Inheritance"), widow of Noonien Soong, "mother" of Data.
- Tal Celes (VOY, "The Haunting of Deck Twelve", "Good Shepherd") Crewman considered inefficient by Seven. Played by Zoe McLellan, better known as Petty Officer Coates on JAG
- Taleen (VOY, "Displaced") Nyrian who explained a new customized habitat to the Voyager crew, as part of the Nyrian's forced relocation scam.
- Taurik (TNG, "Lower Decks") Junior officer aboard the Enterprise-D
- Captain Clark Terrell, captain of the USS Reliant
- Tieran (VOY, "Warlord") Ilaran tyrant ("autarch") who cheated death by transferring his consciousness to other bodies
- Timicin (TNG, "Half a Life") Astrophysicist whose culture tradionally kills people at a certain age
- DaiMon Tog (TNG, "Menage a Troi") Ferengi captain of the Krayton who kidnapped Lwaxana Troi hoping to use her telepathic abilities for profit
- Toman'torax (DS9, "To The Death") Jem'haddar Second to Omet'iklan, executed by his First after fighting with Worf.
- Tora Ziyal, half-Bajoran daughter of Gul Dukat
- Toreth (TNG, "Face of the Enemy") Romulan commander of a warbird, unwittingly helped dissidents defect.
- Tosin (VOY, "Fair Trade") Bandit scamming people trading at the Nekrit Supply Depot
- T'Pau (TOS, "Amok Time"; ENT, "The Awakening" and "Kir'Shara") Vulcan Official, the only person ever to turn down a seat on the Federation council. Leads a rebellion against the Vulcan High Command in the 22nd Century, and a century later officiates at Spock's "marriage or challenge" ceremony.
- T'Pring (TOS, "Amok Time") Unfaithful Vulcan girl who was betrothed to Spock by their parents when they were 7 years old.
- The Traveler (TNG, "Where No Man Has Gone Before", "Remember Me", "Bloodlines"), Humanoid from Tau Alpha C with exceptional mental abilities, including mastery over time and space.
- Trelane (TOS, "The Squire of Gothos")
- Trevean (DS9, "The Quickening") Teplan equivalent to Jack Kevorkian, assisted the suicide of many Teplans afflicted by the blight.
- Ian Andrew Troi (TNG, "The Child"), son of Deanna Troi and space-dwelling lifeform.
- Ian Andrew Troi, father of Deanna Troi
- Kestra Troi sister of Deanna Troi
- Lwaxana Troi, Daughter of the Fifth House, Holder of the Sacred Chalice of Rixx, Heir to the Holy Rings of Betazed (TNG/DS9, various episodes), Betazed mother of Deanna Troi.
- Tuvix (VOY, "Tuvix"), individual created in a transporter accident that merged Tuvok and Neelix.
- Mark Twain (TNG, "Time's Arrow")
- Aquiel Uhnari (TNG, "Aquiel") Comm tech at Relay Station 47.
- Kevin Uxbridge (TNG, "The Survivors") Powerful being repentant for genocide
- Rishon Uxbridge (TNG, "The Survivors") Wife of Kevin Uxbridge
- Vadosia (DSN, "The Forsaken"), Bolian ambassador sent to Deep Space Nine to investigate the Bajoran wormhole in 2369.
- Varria (TNG, "The Most Toys") Assistant to Kivas Fajo for 14 years. Helping Data escape from Fajo's ship led to her death.
- Vash, falls in love with Picard, in the show and in real life
- Veer (VOY, "Distant Origin") Assistant to Professor Gegen.
- Jason Vigo (TNG, "Bloodlines"). Bok, a Ferengi, altered Vigo's DNA to appear as if he was the son of Enterprise Captain Jean-Luc Picard. Vigo was used as bait by Bok so Bok could avenge his son's death (his son was killed by Picard).
- Miranda Vigo Mother of Jason Vigo
- Vorik Vulcan engineer aboard Voyager
- Tim Watters (DS9, "Valiant") Red Squad cadet who commanded the USS Valiant after the death of Captain Ramirez. Portrayed by Paul Popowich.
- Weyoun Vorta male; cloned at least eight times
- Naomi Wildman half-Ktarian, half-human female; daughter of Greskrendregtk and Samantha Wildman; born aboard Voyager; died soon after birth but was replaced by a duplicate; grew up fast due to her father's genes
- Samantha Wildman human female; married to Greskrendregtk, a Ktarian; gave birth to their daughter, Naomi while on Voyager
- Vedek, Kai Winn Adami Bajoran female
- Wixiban (VOY, "Fair Trade") Talaxian male; encountered Neelix at the Nekrit Supply Depot
- Worf son of Mogh
- Colonel Worf (TUC) Captain Kirk's defense attourney.