Some general notes on the crew's national origins:
- Captain Jonathan Archer was born in Upstate New York, but as a child, he moved to San Francisco and spent the rest of his life there. Logically, because Starfleet Headquarters is in San Francisco, his father was nearby working on the Warp 5 engine project, and afterwards Archer himself was around Starfleet Headquarters continuing to work on the Warp 5 test flights.
- Chief Engineer Trip Tucker is from Florida.
- T'Pol and Phlox are aliens, from Vulcan and Denobula respectively.
- Lieutenant Malcolm Reed is from England.
- Ensign Hoshi Sato is from Japan.
- Ensign Travis Mayweather was born on a trading ship during a deep-space run, making him the only human main cast member not from Earth.
Captain Jonathan Archer
The Captain of Earth's first Warp 5 starship, Archer spent most of his life dreaming of going to the stars and, since his father Henry was a major player in humanity's achievement of Warp 5 in the first place, his command is rather personal. This is also where he got his distrust of Vulcans, as they had spent most of his life attempting to keep humanity in and around its own solar system.
- Ace Pilot: He was one of the test pilots for the NX prototypes and handles quite a number of shuttlepod flights. Most notable in "Singularity," in which he manages to fly Enterprise out of a black hole while half-awake.
- Authority Equals Asskicking: Not really in the beginning, where Archer frequently gets into fistfights with various enemies, but pretty much all of them tend to result in him at least getting his ass handily kicked and they just about as often end with him knocked out for the count. He does grow into this trope, but only after he's been pummeled into a thin paste a few dozen times by some aliens who don't like him. And even by some aliens who do like him. He learns by experience.
- Beware the Nice Ones: Archer gives off an "everyday Joe" vibe more than any other captain (which is what happens when your captain is played by Scott Bakula), but beneath that vibe lies a lot of resentment and general insecurity. Archer invokes this trope and uses it to his advantage in "Fusion" when he drops the gee-whiz exterior and calls Tolaris out for his Mind Rape of T'Pol. This of course is truly demonstrated in season 3 where once broken he is capable of a level of violence that includes beating unarmed prisoners.
- Bold Explorer: A classically bold example in the mold of Kirk.
- Butt-Monkey: Most of the captains of Star Trek have their moments, but ol' Jonathan Archer is one of the worst of the lot. All he wants to do is peacefully explore the galaxy, making friends of the many species across the galaxy in the ship his father built, but he continuously ends up putting himself and his ship in ludicrously dangerous situations both by chance and due to his Chronic Hero Syndrome; gets captured constantly, nearly gets killed or sentenced to death countless times; and if the plot requires somebody to get badly injured and/or beaten up by the Villain of the Week that episode, it's him, especially during the first season.
- The Captain: One of the first in Starfleet.
- Catchphrase: "We're making history with every light year."
- Composite Character: Archer could be considered an amalgam of past Star Trek captains. He shares the corn-fed hokum of Kirk's upbringing, Picard's zeal for exploration, Sisko's emotional baggage, and Janeway's greying morality.
- Depending on the Writer: From the m0vie blog:"I think what becomes quite obvious as the third season progresses is that everybody on staff has their own version of Archer. André Bormanis seems like the most traditional Star Trek writer on staff, so it's not surprising that Extinction has a nod toward franchise utopianism that doesn't make a lick of sense...In contrast, David A. Goodman seems write Archer only a shade or two more cynical, trying to avoid harming the Vulcans in Impulse and playing cowboy in North Star; Goodman writes a version of Archer who actually seems more well-adjusted than he was for most of the first two seasons. Sussman and Strong both play up Archer's angst. Braga likes gritty action hero Archer.
Coming from outside the show, Coto writes Archer as the gritty character he needs to be for the story to work, even if Coto's scripts (particularly Azati Prime and The Council) seem to suggest that this is not sustainable in the long term. It is no wonder that Coto was the big fan of the "Archer dies at the end of season three" idea... Azati Prime is the episode that really suggests Archer might have to die to redeem [the Alpha Quadrant], and The Council alludes to it with the death of Degra to redeem the Xindi."
- Designated Victim: The writer(s) need to show that the aliens are hostile? Punch Archer!
- Determinator: The result of being a Designated Victim and resident Chew Toy. He has to be a Determinator to resolve the episode in the ship's favor.
- Disney Death: A couple of times, like at the end of Season 3, he's presumed dead in a Heroic Sacrifice.
- Distressed Dude: He is very frequently captured by the enemy of the week, necessitating an escape coupled with a rescue operation from the crew.
- Eagle Land: Represents Flavor 2, with a United Space of America coloring. Archer has an incredibly hard time comprehending that aliens are, well, alien, and frequently runs in trouble directly resulting from this. It extends even to Phlox and T'Pol at times (and definitely to Vulcans as a whole). He has repeated problems with the Kreetassans precisely because he simply cannot grasp how different their culture is from that of United Earth and becomes angry and frustrated over their complex social protocol.
- In "Judgment," where Kolos mounts a surprisingly stirring defense of Archer that boils down to, "He's a bumbling idiot, but his heart is in the right place."
- The Everyman: Since his era was much closer to the present day, Archer comes across as more of an average Joe rather than an Ace Jack-of-All-Stats or Omnidisciplinary Scientist, compared to other Star Trek captains or even Starfleet characters in general.
- Famed in Story: He gains notice for being the captain of the first warp 5 ship, but it's completing the Xindi mission that makes Earth view him as a hero.
- Fantastic Racism: In early series, he really hates the Vulcans. He gets better later.
- A Father to His Men: He maintains a First-Name Basis with his command staff and will go after any member of his crew who's captured, injured, or stranded with every resource he has. He lampshades this in one episode, commenting that he once had a captain who kept a professional distance with his crew, but given that Enterprise is alone on its missions, the crew has to be more of a family than a group of coworkers in order to survive.
- Fire-Forged Friends: Slowly becomes this with T'Pol.
- General Ripper: In the early half of Season 3. Archer changes his tune pretty damn quickly when he realizes that the Xindi have been manipulated and lied to for generations and have been screwed over pretty severely. The Sphere-Builders are not happy with the outcome.
- Hair-Trigger Temper: While his default setting is fairly pacific and easygoing, Archer in the first few seasons is very easy to frustrate, annoy, or anger. The show does attempt to explain this by noting the many long years of frustration and condescension he and his father have received from the Vulcans, but his impatience and temper usually lead him to ignore valid advice or criticism and bull ahead, heedless of the consequences.
- Heroes Love Dogs: He wouldn't hesitate to stand himself in space go to war with entire planets to save his dog.
- Heroic BSoD: His actions in Season 3 clearly weigh on him, but it's not until Season 4's "Home" that he finally has to deal with it.Archer: [to Hernandez] I lost something out there, and I don't know how to get it back.
- Hurting Hero: Because of the trope below.
- I Did What I Had to Do: "This isn't open to debate!" Mostly in Season 3; he's most definitely not happy about being forced into positions where it's either Shoot the Dog or let billions of humans be destroyed by the Xindi superweapon. The decisions he makes weigh on him quite heavily.
- Informed Ability: We're told he got trained to be a diplomat in "A Night In Sickbay," where he does virtually everything a diplomat should never, ever do. (It should be emphasized that, to be fair, he doesn't do any of the above in the presence of the aliens.) Likewise, for a supposed "skilled" diplomat, he barely tries to hide his utter contempt for the Vulcans. (Though, again to be fair: considering how Ambassador Soval constantly treats him, he may have viewed it as par for the course...)
- The concept of "protocol" is completely absent from his awareness. Even when first contact situations start off positively, Archer almost never bothers to do the research to find out what kinds of customs and cultural rules an alien race may have. Shown twice with the Kreetassans in "Vox Sola" and "A Night In Sickbay". The first time he eats in front of them (considered incredibly vulgar by their standards) and the second time, despite knowing how touchy they are, he brings his dog Porthos to an important meeting taking place in a sacred grove of trees. Guess what happens...
- His attempts to make peaceful first contact in general don't fare any better, typically ending in either a shootout, crewmembers getting taken hostage, or Archer having the stuffing beaten out of him.
- Archer even struggles with cultural differences among humans, finding himself at odds with those who do not share his idealistic notions ("Fortunate Son"), even though he himself will not behave very differently when faced with similar circumstances ("Silent Enemy").
- "Desert Crossing" seems him claiming to be trained in desert survival. However, when picking up supplies for a mission on a desert planet in the same episode, Archer fails to bring along even the most elementary of amenities for a trip to a desert, such as appropriate clothing, sunglasses, sunscreen, or even a plentiful supply of water, and later in the episode, he decides that he and Trip should wander across the desert during the day when one of the fundamental teachings of desert survival says you should always walk during the night and rest when the sun is out.
- He does, however, start to get better in Season 2—with his efforts to end the cold war between the Vulcans and the Andorians. Also, in Season 4, he manages to successfully ensure the cultural reformation of the Vulcans back to the teachings of Surak and prevent an interstellar war, as well as negotiate several disputes between the Tellarites and Andorians, averting yet another conflict. Furthermore, according to the (possibly canon) biography shown in "In a Mirror, Darkly," Archer eventually would go on to serve as an ambassador to Andoria for several years. As such, it makes Daniels' claims that he'll be instrumental in forming the Federation far more believable.
- Jack Bauer Interrogation Technique: Season 3 in particular, where he shoves an alien pirate into an airlock and starts to depressurize it until he talks (with Malcolm hovering in the background wondering what the hell he's doing) and later punches the 20th-century medical tech who was working for the Xindi.
- James Bondage: While previous captains had certainly had their share of captivity, with Archer it is almost predictable, along with the fact that he will also get the snot beaten out of him.
- The Kirk: He's got a Spock in T'Pol and a McCoy in Trip. He tends to lean more towards the Id than Superego.
- Lantern Jaw of Justice: Made of pure glass however, which causes him to be The Chew Toy for every hostile species they encounter.
- Leeroy Jenkins: Archer is the captain you'd want to have a beer with, so to speak. He's not a high-falutin' bigwig with grand ideas about the future of the universe; he just wants to get things done. Which usually means running head-first into situations he doesn't understand, getting beaten up and taken hostage.
- Made of Iron: Good thing, considering how often he gets the crap beaten out of him.
- Mr. Fanservice: In the fourth episode, he almost floats out of his shower thanks to a gravity malfunction.
- No Indoor Voice: In most conversations that aren't one-on-one, Archer's voice would be clearly audible in the back of an auditorium.
- Non-Action Guy: He's quick to jump into fights but clearly has no actual skill or training, consistently going down in one hit. At least for the first few seasons.
- Odd Friendship: With Shran.
- The Resenter:
- Archer feels that the Vulcans held humans back, not allowing his father to live to see his warp 5 engine finally fly. He has to begrudgingly change his position when he gets a glimpse of some of the ethical dilemmas that the Vulcans had to deal with when it comes to humans.
- His Mirror Universe self, still only Number Two on Enterprise, is furious to discover his alternate universe self is already captain and will eventually become the most famous explorer of the era.
- Team Dad: To the Enterprise crew.
- Unresolved Sexual Tension: With T'Pol, mostly in Season 2. This is a rather odd and strangely realistic variation, in that it's more the result of T'Pol being the only humanoid female that he is close to for over a year, her being his trusted second-in-command with all the loyalty and bonding such a position entails (as is consistent with all other Star Trek series), and Archer not having the opportunity to *cough* "release any tension" for a very long time while on the first two years of the mission, rather than the result of any romantic affiliation between the two. It stays unresolved and eventually dissipates as they both find partners that they have actual feelings for.
- Water Polo: Archer played in college (implied to be Stanford) and is still a big fan. A water polo ball appears several times in the series, and he is often seen watching the game in his quarters.
- What the Hell, Hero?: Gets called out on his borderline-amoral or dangerous actions more than once. Usually by Trip.
Subcommander (later Commander) T'Pol
Archer's Vulcan science officer and second-in-command, T'Pol did not like humans when she first joined Enterprise's crew. Of course, as the years wore on, she came to respect her human crewmates more and more, and shifted her loyalty from the Vulcan High Command to Starfleet and, more specifically, Archer, with whom she would develop a strong friendship. (Falling in love with Trip certainly didn't hurt, either.)
- Becoming the Mask: The High Command puts her on the ship to keep the humans from getting into too much trouble. When she's recalled at the start of Season 3, she resigns and joins Starfleet.
- Belligerent Sexual Tension: With Trip.
- Also has hints of this with Archer.
- Boobs of Steel: As a Vulcan, she is physically stronger than any of the humans on the ship. Coincidentally, she is also the only one wearing skintight spandex that showcases her breasts as her normal uniform. Contrast Hoshi, who is less physically-capable, less well-endowed, and wears a considerably more modest unisex jumpsuit.
- Bothering by the Book: The Xindi attack makes T'Pol something of a standard-bearer for TOS-era values, both as the Straw Vulcan on the crew and with Trip implicitly equating her with the Prime Directive and the ethics of peacetime, and making it no secret that he wants her out.
- The Caretaker: In the alternate timeline of "Twilight," T'Pol spent over a decade looking after an amnesiac Archer.
- Comically Missing the Point: Most notably when giving her review of Frankenstein.
- Commander Contrarian: At first, she opposes basically any idea that Archer has.
- Consistent Clothing Style: T'Pol's outfits are generally catsuits with the top half being wraparound.
- Cultural Posturing: Frequently.
- Defrosting Ice Queen: At the start, she's contemptuous of humans and convinced that they'll fail. She gradually develops a respect for their abilities and even their emotions.
- Distaff Counterpart: Probably intended to be this for Spock and/or Tuvok.
- Emotionless Girl: Supposedly. It's become more and more obvious throughout the series that T'Pol has far more difficulty keeping her emotions in check than most Vulcans.
- Expository Hairstyle Change: Subtle, but her haircut gets less severe as she reduces her distance to the crew.
- Future Spandex: Her first uniform was very form-fitting (a la Seven of Nine), but still distinctly Vulcan. She ended up having the most costume changes of any character in Trek, but they're all variations of this trope.
- Hot Scientist: T'Pol is the science officer in addition to being the Number Two. As for the "hot" part, well, Trip and Malcolm sure think so.
- Jerkass: In the early seasons, at least, although it's obvious by the end of Season 1 that she's ready to defend Enterprise and Archer against the High Command if she thinks it's necessary, with hints of Hidden Depths.
- Jerkass Has a Point: Shes not the nicest in her logic, but frequently shell be right and the others will be forced to admit that she has a point after ignoring her.
- Not So Stoic: Over the course of four years, T'Pol undergoes a Mind Rape that brings up traumatic memories of losing her emotional control in a jazz nightclub, remembers repressed memories of a line-of-duty killing (that also led to a loss of emotional control), suffers from Pa'nar Syndrome that degrades her neural pathways (leading to loss of emotional control), becomes addicted to Trellium-D (which causes loss of emotional control), and is infected by a microbe that makes her undergo a premature pon farr (leading to loss of emotional control and clothing). During the Vulcan arc, this trope was hand-waved as T'Pol just having poor control for a Vulcan, and a What Could Have Been plotline for the next season would have been that T'Pol had Romulan ancestry.
- Number Two: To Archer. Even during his early Vulcan-hating days as captain, it's standard for him to give her the ship while he's not aboard.
- Lampshaded in the pilot, where she has a debate with Tucker over the matter (she has a higher rank than him, but since she isn't Starfleet, he argues that she is outside the chain of command).
- Official Couple: With Trip. It turns out that, even in alternate timelines and mirror universes, the odds favor them ending up together.
- Omnidisciplinary Scientist: Although it becomes obvious that, even if she has a wide range of theoretical and applied sciences under her belt (which is somewhat understandable considering she's in her late 60s and has had a long time to study under the Vulcan Science Directorate), she is nowhere near as proficient with hands-on engineering and often requires Trip's expertise.
- Scully Syndrome: Particularly in regards to Time Travel. In spite of all the evidence and personal accounts that Archer gives, she insists that the Vulcan Science Ministry has declared time travel to be impossible.
- The Spock: Always the one to offer the more pragmatic explanation or advocate leaving an alien conflict alone.
- Standard Female Grab Area: Very rarely, if ever invoked. T'Pol has taken far more licks than any female Star Trek character to come before her.
- Straw Vulcan: In Season 1, to the point where it's a Conflict Ball. More than once she would not give the crew basic information on a matter and then act superior when she corrected their subsequent mistakes. Other times, she would give legitimate advice that Archer then ignored, leading to disaster.
- Stripperific: If she's not dressed in her duty catsuit, she's usually wearing pajamas that are one size too small or skivvies.
- Strong as They Need to Be: The second variant, where T'Pol is as strong as the writers need her to be. Unlike Spock whose super strength is fairly consistent, T'Pol often loses fights that she should win — particularly fights against Archer. In one episode, she both flung Phlox across the room AND got subdued by Malcolm at close range within a five-minute span.
- Sugar-and-Ice Personality: Usually ice, but there are moments even in Season 1 where she admits a respect for the captain and crew.
- Token Non-Human: Justified as she's basically forced on the human crew by the Vulcans to keep an eye on them. T'Pol ends up Going Native and joining Starfleet.
- Unresolved Sexual Tension: With Archer. In the alternate timeline seen in "Twilight," the scene cuts out before the audience finds out exactly how the relationship between Archer and T'Pol evolved. However, we do know that, although it does take a good decade plus of constantly caring for him for T'Pol to manifest romantic feelings for Archer, it's her loyalty and bond of friendship with him that is strong enough to make her throw away her career to take care of him in the first place.
Commander Charles 'Trip' Tucker III
Enterprise's Chief Engineer and Archer's long-time best friend, Trip Tucker's "good ol' boy" Southern charm disguised one of the sharpest minds in Starfleet. Between his engineering genius and security head Malcolm Reed's deep and lasting desire to blow things up, Enterprise kept flying even when she probably shouldn't have and exceeded all expectations in the process.
- Belligerent Sexual Tension: With T'Pol. He even spells it out in "Home," where he tells her mother that he felt like they had chemistry (his word) the first time they got into an argument.
- Book Dumb: Basic Algebra eludes him, yet he's an engineer. Although with his habit of Obfuscating Stupidity and hiding his genius, the audience is not entirely sure whether he just consistently pretends to be Book Dumb or actually is. The fact that his understanding of warp theory is second-to-none indicates the latter.
- Cynicism Catalyst: His little sister Elizabeth is killed in the Xindi's attack on Earth in the Season 2 finale. He becomes much more cynical, but bottles up his anger and grief until "The Forgotten."
- Deadpan Snarker: Sarcasm Mode is his mode of choice.
- Famed in Story: By the time of Lower Decks, he's mentioned in the same breath as Captain Kirk as a measuring stick for how cool someone is.
- Fan of the Past: Like Tom Paris in Voyager, Trip has a nostalgia for the 1950s. The majority of movies he shows for Movie Night are from that decade.
- Fire-Forged Friends: He and Malcolm have a rocky start, but after being stranded alone in a shuttlepod together, they become close friends.
- Heterosexual Life-Partners: With Malcolm.
- The Lancer: He's been this to Archer for some time when the series begins.
- Leeroy Jenkins: Trip has a habit of leaping before he looks in combat and isn't usually reluctant when it's time to fight. This gets him killed in the finale, when he decides the best way to get rid of the intruders is to set off an explosion in a room he's in.
- The McCoy: Got the accent for it, too. Is constantly arguing the values of humanity and emotion against T'Pol's logic and rationale. Of course, their arguments tend to find other outlets.
- Mr. Fanservice: "Acquistion" has him running around in his underwear for a good chunk of the time. And well, check out his well-muscled chest in his numerous decontamination scenes.
- Mr. Fixit: A few times, he helps another ship fix a broken system or has to deal with malfunctioning equipment of his own. Even when he visits T'Pol's house, he ends up fixing her mom's fridge.
- Number Two: Early on, anyway. He's actually Number Three, but he's much closer to Archer than the actual Number Two. Lampshaded in the pilot, where he has a debate with T'Pol over the matter (she has a higher rank than him, but since she isn't Starfleet, he argues that she is outside the chain of command). More than likely, he would have been the ship's first officer if T'Pol's assignment hadn't been imposed by the Vulcan High Command.
- Pre-Mortem One-Liner:Trip: There's just one other thing I need to tell you—you can all go straight to Hell!
- Scotty Time: He has to deal with it less than other Starfleet engineers, but he's pretty ticked off when he has to work in it.
- Stupid Sacrifice: Decides to blow up himself and the aliens boarding the ship despite the fact that Archer is out of harm's way and after he knows that security is on the way to deal with the invaders.
- Southern-Fried Genius: He hails from Florida and is the best engineer in Starfleet.
- Speak Now or Forever Hold Your Peace: Subverted. T'Pol declines to declare the kal-i-fee at her wedding to Toss. When her mother suggests that Trip tell T'Pol about his true feelings before the ceremony, he refuses because she's got enough pressure on her.
- Techno Wizard: If you give him a few minutes with a piece of technology (from just about any species), he'll be able to fix it or jury-rig it into something useful for the situation.
- The Watson: Often the one to ask questions that T'Pol could then explain to the audience.
Lieutenant Malcolm Reed
British, shy, quiet, and reserved unless someone was in danger, Reed had a talent for getting himself injured while trying to protect his crew and his captain. As it turns out, he also had a talent for blowing things up, and with Trip's engineering genius, did it much better than the weapons specifications said he should have been able to. Although he started out isolated from everyone, he went on to develop a strong friendship with frequent verbal sparring partner Trip and became an anchor for Archer during the Xindi crisis.
- Ambiguously Gay: Dominic Keating is on record as saying, "God knows I played him gay!" but no one's sure whether he's joking or not. There is some evidence that Reed was slated to be the first gay character in Star Trek, but this was apparently later revoked. Considering he's had significant Ho Yay with at least three characters (Archer, Tucker, and Hayes), however, Keating may not have been joking all that much. It's worth noting that when Enterprise was sent back in time, Malcolm never got married or had kids, and he was the only member of the main cast (and possibly the whole crew) that didn't. Possibly Camp Straight, as he has a string of ex-girlfriends and flirts with various female alien visitors (awkwardly, usually) throughout the series. (And he admitted once to taking notice of T'Pol's bum.) Still, that doesn't prove he's straight; he could always be bisexual.
- An interview with Keating from 2013 confirms the speculation about Malcolm: "I played him so gay ... I mean, it was always rumored that Malcolm was gay, wasn't it?", he says. "It was that one line of his three-line bio, Shy around women, that just shockwaved across the gay community." He includes some remarks on the showrunners' reluctance to portray a gay character onscreen. "I dont want to say it was dry and they didnt want to take any risks, but there was an element of that." 
- Beware the Quiet Ones: Malcolm doesn't really talk much. He lets his guns do the talking.
- The Big Guy: If someone needs to lead a security team through the corridors or a rescue team on the surface, Malcolm's the guy.
- Blood Knight: Reed really likes blowing shit up. Lampshaded when they find a hatch and Reed immediately starts talking about where he can place charges before he even looks for the latch device (which Archer locates within seconds).
- Butt-Monkey: Almost as frequently as Archer, it's Reed who is the designated victim, although he's more an accident-prone victim of circumstances than a constant villain target. He seems like a Redshirt with Plot Armor, forever doomed to be injured or trapped in order to provide dramatic tension. This may also be a symptom of The Worf Effect, given that he is the ship's tactical officer and thus the one who should be most capable at looking out for his own well-being, but also the one who is first to confront danger.
- British Stuffiness: The only Brit in the main cast, Malcolm is noticeably more reserved and uptight than his American colleagues. Well, except when he gets to blow things up.
- Consummate Professional: Despite most of the main characters being in Starfleet, Reed is pretty much the only one who consistently acts like he has undergone military training. This brings him into conflict with the MACOs in Season 3, due to their differing military disciplines and protocols clashing. Lampshaded in "Minefield" when Archer inquires why he was so uncomfortable being invited to dine at the Captain's table. Reed eventually admits that throughout his career, he's tried to remain professional and avoid "fraternization" with his superiors and fellow officers.
- Dark and Troubled Past: He used to be an agent for Section 31. This ends up putting Enterprise in a tight spot in Season 4.
- Deadpan Snarker: Approaches every setback with a certain amount of wit.
- Demolitions Expert: The closest thing they've got. Reed also successfully dismantled a Romulan mine on the ship's hull despite lacking a full understanding of its specs.
- Fire-Forged Friends: He and Trip have a rocky start, but after being stranded alone in a shuttlepod together, they become close friends.
- Genius Bruiser: Malcolm is a very innovative weapons designer, he's good at hand-to-hand combat, and he's quite the tactical thinker. Also, if there is a way to make something explode, he will find it.
- Hates Being Touched: Too bad Archer has No Sense of Personal Space.
- Heterosexual Life-Partners: With Trip.
- Homoerotic Subtext: According to Dominic Keating, it was intentional. He has this with Archer, Tucker, and Major Hayes, at the very least.
- Military Brat: His family served in the Royal Navy for generations. He's consequently very knowledgeable about military matters and personalities.
- The Mole: Although to be fair, it wasn't precisely his fault. In Season 4, Section 31 forces him to hinder Enterprise's investigation into Phlox's kidnapping.
- The Quiet One: Very rarely ventures his opinion in a conversation unless it's asked for.
- Shrinking Violet: Except where his crew's safety is concerned. While he's not timid, he is very uncomfortable around other people and has difficulty making close friendships.
- Socially Awkward Hero: It's more pronounced in the tie-in novels, but even in the series proper, it's obvious that Malcolm has a lot of trouble opening up to people.
- The Stoic: How he's usually seen. He even suggests that Archer abandon him when a mine traps him on a detachable section of hull while a Romulan ship threatens.
- Not So Stoic: In "Shuttlepod One," he confides in Trip that he's upset to be seen as a "grim reaper" and explains that he doesn't want to die, but doesn't want to have unrealistic expectations either. Also, later in the series, he calls out his fellow officers on their seeming lack of reaction to a MACO Redshirt's death, and is visibly upset by just how many people they've lost while in the Expanse.
- Stiff Upper Lip: From attempting to perform a Heroic Sacrifice ("Minefield") or being forced to eat emergency rations that he doesn't like ("Shuttlepod One"), Reed rarely ever complains about the situation. At most, he'll make a dry, sarcastic quip before getting right back to business.
- Stuff Blowing Up: 90% of the time, when Reed is openly happy/gleeful about something, it's related to weaponsusually using them.
- Talking in Your Sleep: He says the word "stinky" in his sleep while having a dream about flirting with T'Pol.
- The Un-Favourite: His father was a life-long Navy man, and has remained aloof, cold, and generally disappointed in Malcolm because he didn't follow the family tradition (Malcolm's afraid of water).
- "Well Done, Son!" Guy: See The Un-Favourite. He starts to thaw out a bit once Archer makes a point of befriending him.
- Why Did It Have to Be Snakes?: It doesn't help to have aquaphobia when your family have served in the Royal Navy for centuries.
Ducky Mallard in space, a Denobulan doctor who volunteered for a medical exchange program to serve as the NX-01's sawbones. Phlox had an unorthodox and almost homeopathic approach to medicine, habitually using alien critters to assist in healing, as well as a curious interest in human "mating habits". Luckily for the crew, he was more skilled than he looked; also quite good at keeping them alive.
- Alien Autopsy: He does a lot of these. With great interest, too.
- Bizarre Alien Biology: He has striped toenails, an incredibly long tongue, and an unusually wide grin. Season 4 reveals that, when threatened, he can inflate his head like a blowfish! Of special note is that he's the first being in the entire franchise, aside from species 8472, that has ever defied Borg nanoprobes without having to be rescued from the Collective afterwards. He had to use a considerably Dangerous Forbidden Technique to do it and required a seriously extended recovery, but again, aside from species 8472, he's the only one to ever last more than a few seconds after being injected before showing signs of assimilation.
- Blue-and-Orange Morality: Much like DS9's Garak, Phlox presents a menu of options to Archer; some legal, others not. His ethics are decidedly neutral. He also tended to be more pragmatic than his Vulcan counterpart (organ-farming from clones, freely supplying T'Pol with drugs). In contrast, T'Pol is increasingly on the side of Roddenberry ethics in Seasons 3 and 4, warning Archer against some of the Doctor's methods.
- Bunny-Ears Lawyer: Very eccentric, but deadly serious when it comes to medicine. Notably, Phlox makes no mention of any qualifications that suggests he should be working on humanoid patients ("As a matter of fact, I've also earned degrees in dentistry, hematology, botanical pharmacology...").
- Bourgeois Bohemian: He's a respected professional in his field, but he's keenly interested in learning about new cultures and attitudes.
- Cheshire Cat Grin:Phlox: [to Archer, as he displays his grin for the first time] Optimism, Captain!
- Crazy Cultural Comparison: His reaction to Tucker nervously informing him that his (Phlox's) wife made a pass at him is to immediately suggest that he sleep with her! Denobulans are polygamists and actively embrace the concept of open marriage.
- Deliberate Values Dissonance:
- Denobulan medical ethics are not precisely aligned to the Hippocratic Oath. For example, he refuses to treat patients without their consent, even if their condition is lethal.
- He also has very few qualms discussing a person's medical information with others, even if he is going behind the person's back to do it (i.e., giving out information about Reed's allergy treatments to Hoshi). No HIPPA in space, evidently.
- Dissonant Serenity: Especially in early episodes, when he seems to be the only one having fun amongst a crew still trying to get used to each other.
- Exotic Extended Marriage: Like all Denobulans, Phlox has three wives, each of whom has two other husbands. It has been stated that the Denobulan homeworld is a single continent that is vastly overpopulated.
- Fantastic Racism: Phlox admits that he has some ill-feeling towards Antarans because of a war the two species fought in the past, but he tried to teach his children to be free of prejudice. Later, he is on the receiving end of this on Earth after the Xindi crisis awakens humanity's own tendencies towards xenophobia.
- Foil: To T'Pol, particularly early on. Though they are both in the "outsider" position, his keen interest and enthusiasm for human culture contrasts her contempt and discomfort with it, and he advises her to be more open-minded.
- Friend to All Living Things: He dearly loves his pets. He also took to Porthos, becoming the one who'd look after him when Archer was away.
- Funny Foreigner: Or in this case, Funny Alien. His Bizarre Alien Biology and Blue-and-Orange Morality are often Played for Laughs in day-to-day interactions with the crew, who are as yet unused to aliens.
- Heavy Sleeper: His species only sleeps once a year, for a period of several days. He's incredibly loopy when a medical emergency forces the crew to wake him up.
- Mad Doctor: When the crew starts becoming obsessed with mundane tasks in "Singularity," Phlox becomes hyper-focused on finding out why Travis has a headache and nearly dissects his brain to solve the mystery. Fortunately, T'Pol steps in with a well-timed nerve pinch. The Mirror Universe version is just as bubbly and curious as regular Phlox, only he really enjoys performing brutal medical experiments.
- The Medic: He has his work cut out for him to keep the crew in shape between space mines and many, many angry aliens.
- Mission Control: John Billingsley is even less mobile than the EMH. Phlox spends nearly all his time on the ship, though he does get out a bit more in the fourth season. No wonder the Klingons abducted him on his trip to the Chinese; they would have been waiting for years otherwise!
- My God, What Have I Done?: In "Singularity," he nearly lobotomizes Travis to find out what's causing his headache and threatens T'Pol with a scalpel when she questions this course of action. Afterwards, he's very subdued and thanks her for intervening before he could do any harm.
- Renaissance Man: In addition to his skill with standard and non-traditional medicine, he apparently is something of an anthropologist, joining the Interspecies Medical Exchange so he could study new species and cultures.
- Sixth Ranger: He was present from the pilot, but Archer added him to the crew at the last minute after they met at Starfleet Headquarters.
- The Stoic: His baseline is more cheerful and friendly than most stoics, but it nonetheless stands out as notable exclusions whenever he shows strong emotions like anger or fear.
- Would Be Rude to Say "Genocide": In "Dear Doctor," he openly refuses a cure to the Valakians, who are the edge of extinction, on the basis that Menk, a more primitive culture sharing the same planet, would thrive.
Ensign Travis Mayweather
Enterprise's pilot, Travis was a "space boomer," born on one of the slow-moving cargo transports launched right after humans discovered warp flight. Since transports usually took years to get between ports, Travis grew up on the cargo ship ECS Horizon and probably knows more about living in space than anyone else on board. This also translated into a talent for flying spacecraft.
- Ace Pilot: He's the helmsman for the whole of the series and maneuvers Enterprise through some very tricky situations, including the highly dangerous Delphic Expanse. He also manages to figure out how to pilot a Xindi-Insectoid shuttle despite it being designed for someone with compound eyes.
- Advertised Extra: To absurd degrees. He's one of the least-developed "mains" in Trek history. It seemed like he was going to get some characterization in Season 2 with the episode "Horizon", but most of his dialogue in other episodes were cut or made into offscreen events. Season 4's writers actually gave him some important stuff to do, but it seemed odd to have the others acting chummy with someone they'd barely interacted with previously.
- Badass Adorable: Has his moments.
- Catchphrase: Mayweather loves to frequently remind people "Did you know I've been in space?!"
- A Day in the Limelight: We meet his family and titular home ship in the episode "Horizon."
- Clark Kent Outfit: Somehow, despite wearing a nearly skintight uniform, his clothes function as this. The man is jacked.
- Informed Ability: Phlox is the biologist, Hoshi the linguist, Trip the mechanic, and Travis...the climbing expert. Pray tell, how do you become a climbing expert when you live in space? It really came in handy, too, considering he gets hurt while climbing three times on the show.
- Lesser Star: Although he's billed as a member of the main cast, he usually has very little focus apart from his capacity as the helmsman, and he rarely goes beyond being The Generic Guy characterization-wise.
- Like Brother and Sister: With Hoshi.
- Mandatory Line: Sometimes not even given afforded this much by the writers. Seriously, it reached a point where he didn't even say "Aye, sir". Mayweather's subplots tend to involve being injured and sent to sickbay, simply in order to give him at least some dialogue.
- Mr. Fanservice: Welcome to the gun show. If this Starfleet gig doesn't work out for him, Mayweather can always model underwear.
- Naïve Newcomer: In the first season, at least, despite having lived in space his whole life. Possibly it was intended as being a newcomer to Starfleet, but as noted, his lack of development makes it hard to say.
- Nice Guy: He's one of the more consistently upbeat members of the crew.
- Token Minority: Unfortunately, his lack of development essentially made him this.
- Wide-Eyed Idealist: Usually the one most likely to see things with a black-and-white mentality.
- "Well Done, Son!" Guy: In "Horizon," he notes that his dad, the captain of a cargo ship, was disappointed that Travis didn't follow in his footsteps. Following Mr. Mayweather's death, Travis confides in Archer his regrets over never having reconciled with him. Archer, though, reveals that when he was looking through the candidates for helmsman, Travis' father provided the shortest recommendation he had seen, writing "he'd never met a more natural stick and rudder man in his life" and that Archer would be a fool if he didn't pick him.
Ensign Hoshi Sato
Not a fan of space travel, getting eaten, or aliens, Hoshi Sato was on Enterprise for one reason: She had an unmatched gift for languages. In the days before the Universal Translator, she was a critical part of First Contact missions, especially since she would go on to invent the aforementioned Universal Translator.
- All Asians Know Martial Arts: In Season 4, Hoshi is retconned with a black belt in Aikido to make her more of an Action Girl (whereas in the Season 3 Xindi War arc, she's shown learning simple take-downs from the MAC Os with no mention of these skills).
- Badass Bookworm: Although she rarely gets the opportunity to show it, when Phlox is kidnapped in Season 4, she kicks ass!
- Boldly Coming: In "Two Days and Two Nights." While the others have run-ins with hostile forces on Risa, Hoshi winds up being the only one who gets laid. Get it, girl.
- The Chick: She's one of the most openly emotional (in the "sensitive" vein, not "angry and Hot-Blooded") officers, especially in the first season when she doesn't have much confidence in herself. She is also one of the friendliest bridge officers.
- Claustrophobia: Played up in "Fight or Flight." Archer is stunned to find this out right before a mission, but Hoshi is quick to remind him that he talked her into taking the position.
- Cunning Linguist: It generally takes her just a few hours to start getting the hang of a new language.
- Downer Ending: The Mirror Universe episode reveals in a barely-visible text blurb that Hoshi ends up marrying, leaving Starfleet, and settling on Tarsus IV, where she is ignominiously executed by Kodos during a famine (a young James T. Kirk is witness to her death). The set designer for that episode has said not to take that as canon, though.
- Fighting from the Inside: When the Xindi-Reptilians inject her with brain parasites to make her decrypt the superweapon's launch codes. She manages to add a new layer of encryption, although the next set of parasites forces her to comply.
- Fish out of Water: She's really uncomfortable with space travel with the weirdness and dangers involved.
- The Gift: Hoshi is not just a Cunning Linguist; one telepathic alien points out that it seems that her brain is uniquely wired for multiple languages.
- The Heart: She's shown to be close with all of her fellow bridge crew and often spends her downtime getting to know new people, or trying to, as with the MACO squad.
- Heroic BSoD: After being rescued from the Xindi thanks to brain scrambling and guilt over not being able to prevent the Xindi from hijacking her skills.
- Ironic Fear: Anything space-related. This was later echoed by McCoy in the first J.J. Abrams Trek film.
- Like Brother and Sister: With Travis.
- Meaningful Name: Hoshi means "star." Sato means "journey." Therefore, Hoshi Sato, more or less, translates to Star Trek.
- Nervous Wreck: Shes very anxious at first, feeling like shes useless for screaming at dead bodies, and not able to sleep on one side of the ship.
- Omniglot: It comes naturally to her. It's the reason she's on the ship.
- Out of Focus: Relatively prominent in Season 1, she gradually gets less and less to do. Season 2's "Vanishing Point" literally has her slowly fading away, which is almost too good a metaphor. Season 4 gives her a few more moments of spotlight, culminating in one instance of her in command of the ship.
- The Pirates Who Don't Do Anything: When was the last time we actually saw her translate something? It's not entirely her fault; Archer seems to go out of his way to find her tasks that involve everything but her actual job.
- Shrinking Violet: Hoshi's definitely very sweet, but a little socially awkward and shy at first. She shakes this off by the end of the series, with what little Character Development she gets.
- The Starscream: In the Mirror Universe. As the crew put it, the episodes "Put the Ho back in Hoshi."
- Tomboyish Ponytail: Often has this throughout the series.
- Took a Level in Badass:
- Hoshi suddenly acquires martial arts skills in Season 4. In the penultimate episode, the former Shrinking Violet not only commands the ship but also takes on the Minister of Earth in a battle of wills and wins. (Which sort of suggests that Starfleet is a bit too comfortable with ignoring the civilian government. Might explain why every third admiral was planning a coup from ST VI on.)
- In the Mirror Universe, Mirror Hoshi manages to take on Mirror T'Pol in a knife fight and hold her own for some time. T'Pol only loses because after she knocks Hoshi down for the count, she gets shot In the Back by a MACO. Mirror Hoshi would then go on to become Empress of the Terran Empire!
Archer's utterly adorable beagle.
- Angry Guard Dog: In the Mirror Universe, Porthos is a snarling Rottweiler. Beagle Porthos can't quite compete in that area, but when Ferengi board the ship in one episode, he does his best to bark his disapproval.
- Evil-Detecting Dog: In "Anomaly," he sits up and starts barking before the ship is rocked by a massive spatial anomaly.
- Meaningful Name: He was part of a litter of four males, dubbed "the Four Musketeers", hence how he got the name "Porthos."
- Precious Puppies: Okay, so he's a mature dog, but still...
- Silent Snarker: Often, Archer will mull over his thoughts out loud, play-acting his inner struggles as conversations with Porthos. On occasion, we cut to the dog's reactionthen back to Archer, who says something like, "Yeah, you're right," and otherwise acts like Porthos just chided him. He also gives the visiting Ferengi a real barking-to. Ah-hem...
- The Ace: Specifically designed to be the best starship of the United Earth Starfleet, and is the first to reach warp 5.
- The Speechless: Unlike future starships, Enterprise doesn't give vocal responses to commands.
- Took a Level in Badass: Several times. First is when Trip and Malcolm upgrade her weaponry with phase cannons (the precursors to phaser banks). Then, after the Xindi attack, she gets photonic torpedoes, improved hull plating, and a contingent of Space Marines, turning her into a full-fledged warship. (Word of God suggests that if the show had gotten a fifth season, she could've received far more extensive upgrades.)
Other Starfleet/Human characters
Vice Admiral Maxwell Forrest
- "Well, this may come as a surprise to you, Jon, but the Vulcans aren't talking."
The crew's Reasonable Authority Figure based on Earth, Forrest was also not a fan of Vulcans. He was, however, Archer's friend and patron, and was unusual for an Admiral in that he actually helped the crew instead of hindering them.
- Casting Gag: Vaughn Armstrong had been playing various characters in the franchise since the early days of TNG. Forrest, however, was the first time he played a human.
- Heroic Sacrifice: Dies protecting Soval from a terrorist attack on Vulcan. His death inspires Soval to re-evaluate his position concerning humans and leads to greater cooperation between the two races. He even fulfills the trope in the Mirror Universe where he's captain of Enterprise, Going Down with the Ship so his crew will have a chance to escape.
- Mythology Gag: The three Admirals seen in "Broken Bow" are Admirals Forrest, Leonard, and Williams, after DeForest Kelley, Leonard Nimoy, and William Shatner, respectively. As Kelley had died roughly a year prior to the start of filming, Forrest has, by far, the largest role in the show.
- OOC Is Serious Business: "First Flight" is the first time we see him get angry at Archer.
- Reasonable Authority Figure: Forrest is Archer's patron and friend; somewhat unusual for Star Trek, where admirals tend to be indifferent or outright hostile towards the crew, or go insane. On the rare occasions where he disagrees with Archer's decisions, he does acknowledge that Archer and Enterprise are the ones in the thick of things and will back his play. Even his Evil Counterpart in the Mirror Universe is respected more than he's feared.
Major J. Hayes
The commanding officer of a group of MACOs detatched to Enterprise on their mission to the Delphic Expanse after the Xindi attack. His very straightforward and military demeanor highlights the change in their mission as well as causing some friction with the existing crew.
- The Big Guy: He and his platoon are explicitly military and trained for combat. Their skills are very useful on various infiltration misions.
- Consummate Professional: Hayes is even more military than Reed is, with his training regimens and never forgetting to append his statements with "sir" or "ma'am."
- A Father to His Men: Downplayed, but noticeable. He's upset when his people die on missions he's not leading because he feels personally responsible for everyone on his team.
- Interservice Rivalry: He and Reed clash over security and military operations at first, which culminates in a fistfight. They eventually understand each other better.
- Just Following Orders: In "Hatchery," he admits after it's all done that the others had to mutiny because he would have kept following Archer's enzyme-induced orders even if they had explained their concerns to him.
- Mauve Shirt: He's the leader of a squad of Red Shirts, although the MACOs actually have a pretty good survival rate for that trope. He dies right at the end of rescuing Hoshi, shot during beam-out.
- No Name Given: His first name is left as "J." His actor and Expanded Universe materials name him "Joss," "Jeremiah," or "Jay."
- Space Marine: He and his squad are tough, serious, combat-ready fighters who don't fraternize much with the rest of the crew; they're there to fulfill a mission.
Captain Erika Hernandez
- "I'm married to Starfleet...just like you."
Archer's old flame and the captain of Enterprise's sister ship Columbia (NX-02), Erika Hernandez was a fiery Action Girl who appeared in only three episodes of the show's fourth and final season. Somebody liked her, though, because she played a major part in the previous novel verse.
- Action Girl: Gets as down and dirty in combat as any of the boys.
- Hero of Another Story: Her time on the Columbia, which could easily have been the basis for its own spinoff.
- New Old Flame: To Archer. They were forced to break up when he was promoted and she wasn't, but it's made quite clear that they've never really gotten over each other. Once she gets her promotion, they rekindle their romance.
- Replacement Flat Character: Hardened by the Xindi mission, Archer draws this kind of comparison to her.Archer: I look at you, and I see the person I was three years ago—the explorer that my father wanted me to be.
- Retcon: Her presence as a starship captain undoes the 30-year-old embarrassment of "Turnabout Intruder," which claimed that women were forbidden from that position, apparently confirming the long-held Fanon belief that this was another one of Janice Lester's delusions and Kirk couldn't be bothered to argue with her.
Captain Archer's steward... supposedly. He's actually an undercover Timecop stationed on Enterprise to help them through the Temporal Cold War.
- Ambiguously Human: Apparently.Archer: Are you human?
Daniels: More or less.
- Body Horror: When he reappears in "Storm Front", he's... not in a good way. Due to time going all monkey-flark, various parts of his body are different ages.
- Covert Group with Mundane Front: "Captain's steward" is probably the least-illustrious position on the ship... but it gives him immediate access to Archer and allows him to build up a base of trust, while allowing him to observe events from an inconspicuous position.
- Death Is Cheap: Doubtlessly owing to the fact that he's a time traveler. When he shows up after getting shot in his first episode, he tells Archer that he only died "in a manner of speaking." It happens again in the Season 4 opener. And unhappens in the second half of the Season 4 opener.
- The Mole: A benevolent one, as he was assigned to protect Enterprise in general and Archer in particular.
- Never Give the Captain a Straight Answer: Justified since he can't say too much or risk messing up the timeline.
- Nice Job Breaking It, Hero!: His bringing Archer to the future causes the destruction of the entire Federation, stranding the two of them in a ruined 31st century. "Whoops" just doesn't quite cut it here.
- No Name Given: His first name is never revealed. (If he has one.)
- Put on a Bus: Once the Temporal Cold War arc ends with "Storm Front", Archer tells him to get the hell out of his life and never come back. And he doesn't.
- Remember the New Guy?: He doesn't actually show up until the episode where he reveals his identity.
- Time Police: He's a temporal agent from the Federation of the 31st century and gives Archer various assignments, which Archer is never happy about.
Archer and Daniels' main adversary in the Temporal Cold War. He's the head of the Suliban Cabal, a group of genetically-enhanced Suliban who want to change history to their advantage, which is apparently to humanity's disadvantage.
- Arc Villain: He's the main bad guy of Season 1, doesn't show up as much in the second season, and is largely replaced by the Xindi in the third. He comes back for the Season 4 opener.
- Enemy Mine: He teams up with Archer to fight Vosk in "Storm Front" because Vosk wants to destroy the Suliban too.
- First-Name Basis: He's fond of calling Archer "Jonathan."
- Karma Houdini: In "Shockwave, Part 2," he escapes after helping cause massive destruction in the preceding episode.
- Killed Off for Real: In the fourth season opener.
- LEGO Genetics: He can shapeshift and compress his body to squeeze through narrow spaces thanks to genetic modifications.
- Smug Snake: Often. In "Storm Front, Part 2," it gets him assaulted by Archer.
- Worthy Opponent: He calls Archer one in "Storm Front."
The Suliban Cabal's Mysterious Employer from the future, who gifts them genetic enhancements in exchange for their obedience. Though primarily an antagonist to the crew of the Enterprise, little is known about his true motivations.
- Ascended Meme: Fans dubbed him "Future Guy." Then the writers started labeling him that in scripts.
- Big Bad: Of the Temporal Cold War arc
- Expy: As the shadowy benefactor of a group of alien antagonists who appears via a blue-tinted hologram, his role is reminiscent of Darth Sidious in The Phantom Menace.
- The Faceless: We don't ever see his face.
- Hidden Agenda Villain: We never actually find out what he's changing history for. In the Star Trek Expanded Universe, it's revealed that his manipulations of time were motivated by a desire to ensure his own existence, making him something of an Anti-Villain.
- The Man Behind the Man: For the Suliban Cabal; they follow his orders.
- The Omniscient Council of Vagueness: A one-man band version.
- Set Right What Once Went Wrong: He tells Archer about the Xindi attack to ensure Earth won't be destroyed. At first, he seems motivated by little else than Even Evil Has Standards but, as Season 3 later reveals, had the Xindi succeeded, it would've doomed the entire galaxy.
- Sinister Silhouettes: We only see him like one of these.
- What Might Have Been: Word of God has it that the original "idea" was that "Future Guy" was originally supposed to be a Romulan, presumably tampering with the timeline so as to ensure victory for the Empire in the upcoming (for Archer and company) Earth-Romulan War. As time went on and the Temporal Cold War was developed further (such as it was), the Romulan idea was dropped. Years after the fact and with the Temporal Cold War still unresolved, Brannon Braga casually dropped the reveal◊ that, well... Archer did it. (This reading, if it is to be believed, makes the time travel arc even more nonsensical.)
Duras, Son of Toral
A Klingon with a serious grudge against Archer after an incident involving refugees fleeing the Klingon Empire.
A Xindi-Primate leader and the man who fired the prototype weapon on Earth. Killing seven million people has a profound effect on him, eventually making him open to talking with Archer.
- Anti-Villain: He truly believes it's a choice between his people or humans. When Archer proves that he's been lied to, Degra allies with him.
- Family Values Villain: Has a wife and two children. He wants to protect them, but being a father also gives him a lot of guilt thinking about how many children he killed on Earth.
- HeelFace Turn: After Archer reveals to Degra that the Xindi are being manipulated, Degra becomes an ally of the Enterprise crew.
- I Did What I Had to Do: This is what he continually tells himself about attacking humanity.
- Mind Rape: Archer subjected him to amnesia and a prison break simulation to try and get information on the Xindi superweapon from him.
- Punctuated! For! Emphasis!: In his defense, he's under a lot of stress throughout the third season.
The second Xindi-Primate representative and Chairman of the Xindi Council.
- All There in the Manual: He isn't named in the show. His name comes from the novelization of "The Expanse"/"The Xindi."
- Anti-Villain: He's doing what he believes is in the best interest of the Xindi people, because his gods have lied to him.
- Everyone Has Standards: He's utterly disgusted by the Reptilians' aggressive callousness.
- Reasonable Authority Figure: While he doesn't initially believe Archer's testimony, he does his utmost to ensure that he gets to say what he came to say.
The Xindi-Arboreal leader, and a friend and confidant of Degra.
The Xindi-Aquatic leader.
- Reasonable Authority Figure: She's usually the one keeping the other Xindi from going at each other's throats. She's also willing to listen to Archer, even though swaying her is no simple task.
The Xindi-Reptilian leader. He's very eager to carry out his people's mission to destroy humanity.
- Berserk Button: Any insults to his intelligence.
- Dragon Ascendant: Takes center stage as the main villain in the last part of Season 3, working to forward the Sphere Builder plan.
- Even Evil Has Standards: Dolim gets more than a little ticked off at the Sphere-Builders for his having to create a rift among the Xindi Council. Milder than most examples of the trope, though.
- Fantastic Racism: He holds a strong contempt towards the human race. And generally anything that's not a reptile.
- General Ripper: And how.
- Offing the Offspring: Degra recounts a story about how Dolim's daughter gave birth to a son was born with a deformity which wasn't life-threatening but would've prevented him from serving in the military. Dolim thus had his own grandson poisoned. While Degra notes it might not be true, what we see of Dolim is enough to suggest it easily could be.
- Reptiles Are Abhorrent: Of all the Xindi, he's the only one who remains unwilling to listen to Archer's side.
- The Social Darwinist: Sneers at the fate of the Xindi-Avians, claiming the Xindi Council's world smells "of a race that failed to survive".
- Unwitting Pawn: For the Sphere Builders's plan to wipe out all life in the galaxy.
- Why Am I Ticking?: Archer kills him by sticking a bomb on him.
- You Have Failed Me: Seems to love threatening to do this...and occasionally carrying it out.
The head of Vulcan High Command who is secretly working with Romulans to unite them with the Vulcans.
- Bad Boss: He's noticeably angered and subverted the other members of the Vulcan high command, and makes one of his men The Scapegoat for the destruction of the Earth embassy.
- Call-Forward: He's working to reunite the Vulcans and the Romulans, a cause that Spock later takes up by the TNG era.
- Casting Gag: It's not the first time Robert Foxworth has lead The Conspiracy in Star Trek.
- The Conspiracy: He and some of his subordinates are acting to launch a pre-emptive strike on the Andorians, and he's trying to subject the pacifist Syrranites to The Purge. Oh, and he's working with the Romulans for reunification...
- President Evil: The script literally notes that he's the closest thing Vulcan has to a planetary president, and the above tropes explain the evil part.
Dr. Arik Soong
The ancestor of Noonien Soong, imprisoned for genetic experimentation. Archer seeks his help in tracking down a group of Augments wreaking havoc with a Klingon bird-of-prey, but Soong soon breaks away and joins his "children" in trying to prove that they're not that bad, really.
- Anti-Villain: He causes loads of trouble for Archer (including bringing Orions down on them, which results in several crewmembers ending up in a slave auction), but when he infects a hostage with a horrific virus to make the Starfleet doctors talk, he's the one who breaks down and begs them to "let" him end it. When his Augments turn out to be inveterate assholes after all, he's quite regretful.
- Call-Forward: After returning to custody, he decides to turn his attention to cybernetics, foreshadowing Data, Lore, and B-4.
- Deadpan Snarker: He's mocking and condescending towards Archer and the Enterprise crew.
- Even Evil Has Standards: He doesn't like anyone getting killed. However, if he feels like it's necessary, he will allow a sacrifice to be made for his cause.
- Evilutionary Biologist: He was incarcerated for stealing Augment embryos and is an advocate of genetic engineering, which has been outlawed by the 22nd century.
- Family Values Villain: He considers the Augments to be his children.
- Identical Grandson: At this point, some fans think that Noonien is a straight-up clone.
- Papa Wolf: He's not too thrilled to hear that Malik killed his brothers.
- Techno Wizard: The guards only let him use paper because he once used a single PADD to open every single lock in the prison.
- Uncanny Family Resemblance: Looks just like his descendant, Noonien Soong, and by extention, Data, Lore, and B-4.
- Villain Has a Point: A lot of the theoretical papers he writes in prison propose cures and treatments to various diseases, including the one that killed Archer's father. Phlox also agrees that gene therapy is useful (and widely practiced in Denobulan medicine), but believes that humanity's experience with the type that Soong wants justifies their zero-tolerance policy on it.
- Well-Intentioned Extremist: He wanted to prove that genetically-engineered humans didn't always have to turn out like Khan. Unfortunately, his "kids" have turned out like Khan.
A Romulan officer plotting to avert the alliance that will eventually become The Federation.
John Frederick Paxton
The leader of Terra Prime, a supremacist group that wants aliens to leave Earth. He creates a binary clone of a Vulcan-Human child from Trip and T'Pol's DNA to show the "horror" of what's to come.
- Benevolent Boss: He's rather nice and respectful to his mooks, as long as they haven't outlived their usefulness.
- Break Them by Talking: He attempts to inflame Archer's old prejudice against Vulcans with barbs about how his father was held back by them.
- Catchphrase: "Terra Prime... forever."
- Chekhov's Skill: Due to many years working as a Martian miner, he's able to continue functioning in a low oxygen environment, overpowering Archer and firing his superweapon in the episode's finale. Fortunately, Tucker is able to redirect it harmlessly into the ocean.
- Deadpan Snarker: He delivers a handful of darkly witty lines.
- Fantastic Racism: Although much of his group was inflamed by the Xindi attacks, Paxton himself applies the views of Colonel Phillip Green, a 21st-century eco-terrorist who ordered the murder of hundreds of thousands of humans suffering from radiation sickness so their descendants wouldn't suffer.
- Final Boss: The Big Bad of the "Terra Prime" two-parter, he's the last major villain faced by Archer's Enterprise and ultimately humanity's final obstacle to the formation of what will become the Federation, with the Rigel pirates from "These are the Voyages" serving as a Post-Final Boss of sorts.
- Hostage Situation: He points a giant space cannon at Starfleet Command and orders all non-humans out of the Sol system or he fires.
- Hypocrite: He espouses anti-alien views, yet he relies on Rigelian gene therapy to extend his own life due to being addled with Taggart's Syndrome. T'Pol threatens to tell his followers, but he scoffs at the idea of them trusting an alien over himself. His disease also means that if he had lived during the Post-Atomic Horror, his idol Colonel Green would've had him euthanized.
- Killed Offscreen: The Star Trek: Enterprise Relaunch novels confirm that Paxton did go to prison for his crimes and died there of Taggart's Syndrome.
- You Have Failed Me: He orders the baby's minder killed for getting too attached to her.
Other recurring characters
- "We don't know what to do about Humans. Of all the species we've made contact with, yours is the only one we can't define. You have the arrogance of Andorians, the stubborn pride of Tellarites. One moment, you're as driven by your emotions as Klingons, and the next, you confound us by suddenly embracing logic."
The Vulcan ambassador, he doesn't trust humans one bit and attempts at all costs to stump them at every turn. T'Pol was his original partner in crime, until she became the mask and decided she'd rather throw her lot in with the humans.
- Ambadassador: He has since left that part of his life behind, but a hundred years before the start of the series, Soval was a member of the Intelligence division of the Vulcan High Command. He negotiated one of their original treaties with the Andorians while he was stationed on an occupied planet as part of the occupying forces, and when he returns to that same planet a hundred years later, he is able to keep walking and shooting (albeit without hitting anything) even after having been shot.
- "Ass" in Ambassador: Soval is an annoying Jerkass until Admiral Forrest gets killed off trying to protect him in the fourth season. Then he cooperates with Archer. And even then, he's kinda pushy.
- Gentleman Snarker: In his better moments.Soval: You heard Captain Archer: The "ball" is in our "court."
- Insult Backfire: When he says he's developed an affinity for Earth and its people, Trip remarks that he did a pretty good job of hiding it. Naturally, Soval takes this as a compliment.
- Jerkass Has a Point: His skepticism of humans becomes clearer in "The Forge," where he explains to Forrest that he (and other Vulcans) have long noticed an uncomfortable similarity to themselves. Both species were nearly wiped out by war, managed to re-build their worlds and then began exploring the galaxy, but while it took Vulcans 1500 years to do so, humans did it in less than 100.Soval: [to Forrest] There are those on the High Command who wonder what humans would accomplish in the century to come, and they don't like the answer.
- Knight in Sour Armor: In the Mirror Universe, he's a former idealist beaten down by the brutal Terran Empire. As with Mirror Spock, he has a Beard of Evil but is not evil himself.
- Surrounded by Idiots: Seems to be his normal attitude, particularly when in a non-Vulcan environment. Still, even Vulcans are not immune, as indicated by his attitude in Season 4 when standing before the High Command.
- Took a Level in Badass: Despite being a desk-bound Obstructive Bureaucrat, Soval manages to withstand Shran's Cold-Blooded Torture and win the Andorian's respect for not breaking.
- Took a Level in Kindness: He becomes much more cooperative with Archer and the Enterprise crew come Season 4.
Commander Thy'lek Shran
- "Tell Archer that's two he owes me!"
An officer in the Andorian Imperial Guard and captain of the battle cruiser Kumari. Although Andorian interests often put him at odds with the Enterprise crew, Shran and Archer develop a mutual respect and end up working together on a number of occasions. He would have become a main cast member in the unproduced fifth season, had the show not been cancelled.
- Byronic Hero: In fact, ALL Andorians are walking Romanticism incarnate, praising emotion and the experience of passion; ritualizing the concept of a duel to settle differences, housing probably the greatest Art Academy in the United Federation of Planets...and thoroughly disagreeing with Vulcans (Realists and Rationalists).
- The Cavalry: Shows up in the nick of time and destroys a Xindi warship that was about to shoot down Archer's shuttle which, in turn, would have allowed the Xindi superweapon to destroy Earth unopposed.
- Commanding Coolness: Probably the coolest individual to hold that rank in the entire franchise.
- Commonality Connection: In Season 4, upon learning of the long history of Enterprise from Archer, Shran relates that his ship, the Kumari, was similarly named for the first ice cutter to circumnavigate Andoria. It's the first moment in which their animosity begins making way to a true friendship.
- Debt Detester: Specifically to Archer, though it's a Zigzagged Trope with You Owe Me. However, this back-and-forth provides a basis for trust between two men who aren't always on the same side due to politics or opposing values.
- FaceHeel Revolving Door: He starts as an antagonist, but then he helps Archer because he feels a personal debt, but then he's robbing a Xindi prototype from him, but then he's The Cavalry... Mainly, it's because he personally likes and trusts Archer and Enterprise, but the Imperial Guard is always ordering him to oppose Archer.
- No Guy Wants an Amazon: Averted; his Number Two Talas makes what he describes as an aggressive overture towards him, leaving Shran with a choice of charging her with assaulting a superior or mating with her.
- Obfuscating Stupidity: Plays at being a greedy miner looking for minerals to fool some Xindi weapons testers.
- Odd Friendship: Develops one with Archer.
- Politically Incorrect Hero: More than a little racist towards Vulcans, Tellarites, and "pinkskins" (humans).
- Properly Paranoid: Most notably in "The Andorian Incident."
- Proud Warrior Race Guy: He's quite a busy one, commanding an infantry regiment on a contested colony and also having his own ship for over a decade.
- Second Love: After the death of Talas, he eventually moves on and, by the time of "These Are the Voyages", has married the Aenar Jhamel.
- Sour Supporter: Somewhat in "Proving Ground." He does as he's told, but tries to convince his superior that humans could be a valuable ally instead of mere pawns to be manipulated.
- With Friends Like These...: Although arrogant, militant, and speciesist (his favorite nickname for Archer is "pinkskin," and he loathes Vulcans and Tellarites), he has a strong sense of personal obligation and provides more practical help than humanity's Vulcan "allies" during the Xindi crisis. Nevertheless, Shran often causes as many problems as he helps to solve.
- Call-Forward: Her presence.
- Fantastic Racism: She's mistrustful of humans and thinks the only reason Syrran mind-melded with Archer was because there was no other choice. She's rather taken aback when Surak's katra chooses to stay in Archer's head and re-evaluates her views.
- Foregone Conclusion: That she was framed. It's not that likely that the distinguished figure Kirk wants to impress was really a terrorist who once attacked Earth's embassy.
- The Fundamentalist: She and the other Syrranites are accused of this, and they have to live in a particularly brutal part of Vulcan to avoid persecution. In truth, they're much better followers of logic than 22nd-century Vulcan society.
- Good Is Not Nice: She openly says she would try and force Surak's katra out of Archer even if he wasn't volunteering, justifying B'Elanna's statement that she could be "ruthless" in her logic. She is, however, rather nice to T'Pol after T'Pol's mother dies.
- Older and Wiser: Inverted. T'Pau is very logical and driven in her younger days, but she's also mistrustful and doesn't yet have the benefit of Surak's original teachings to guide her.
- The Spock: To Archer's chagrin, she shoves him down an escape tunnel with the Kir'Shara rather than letting him retrieve T'Pol, who was knocked out in the fight with Vulcan cops. Getting the artifact to the capital is more important.note