Katma Tui was a Green Lantern, and trainer of new recruits to the Corps. She had a brief, romantic relationship with John Stewart.
- Green-Skinned Space Babe: Orange skinned.
- Interspecies Romance: She (a Korugarian) had a brief romance with John (a human).
- Mentor: To most of the other Green Lanterns. John Stewart even compares her to Yoda at one point.
- Ms. Fanservice: In her first appearance, she wears a regular GL uniform. When she reappears in "The Return", she is wearing a sexier, customized version of the outfit. And in "Hearts and Minds" she dons a rather Stripperific "priestess" outfit.
- Sexy Mentor: To John Stewart.
- Stern Teacher: She is not particularly warm or kind when training her students.
- Teacher/Student Romance: It is all but said out loud that she had one with John while training him as a Green Lantern.
Kilowog was a member of the Green Lantern Corps.
- Ace Custom: Interestingly, he is given an upgraded Green Lantern armor uniform when he goes to confront AMAZO, even though GL uniforms are explicitly mental constructs.
- Adaptational Nice Guy: In contrast to most versions of the character, Kilowog is the most kind-hearted of the Corps members shown.
- Big Eater: Even moreso than The Flash.
- The Engineer: His other skill outside of his Green Lantern powers. In "Hearts and Minds", he is able to rapidly construct a carbon bomb with relative ease.
- Extreme Omnivore: At one point, he eats a videotape, proclaiming it to be delicious.
- Odd Friendship: With Flash. They bond over their mutual friendship with John Stewart, their wise-cracking personalities, and their love of food.
- Pig Man: Which makes Flash inviting him to a bratwurst cookout all the more hilarious.
- Redemption Earns Life: Notably in "Blackest Night", he was the only member of the Green Lantern Corps to speak up for and defend John Stewart's character during his trial (albeit after some convincing from Hawkgirl). Later in "Hearts and Minds", several of his colleagues are killed in battle while he is spared and would go on to become a semi-regular Recurring Character.
Captain Marvel (Billy Batson)
Captain Marvel was a superhero who protected Fawcett City, and a former member of the Justice League.
- Ascended Fanboy: He openly admits to idolizing the Justice Leaguers (especially Superman) before briefly joining himself.
- Broken Pedestal: Superman's paranoid behavior during Marvel's time on the Justice League makes him lose a lot of respect for someone that he once idolized.
- The Cape: Is arguably an even bigger archetype of this trope than Superman himself, much to the latter's annoyance.
- Manchild: Comes off like this towards the rest of the League sometimes (who are unaware that his secret identity is a child).
- Nice Guy: His cheerful and positive attitude rubs off so warmly on the Justice League that even Batman takes a liking to him.
- Older Alter Ego: Billy and Marvel.
- The Pollyanna: Has a rather sunny and optimistic approach to being a superhero.
- Unwitting Pawn: Of a Batman Gambit that Lex Luthor and Cadmus performed on Superman to make him look bad in public.
- Wide-Eyed Idealist: He's far far towards the ideal end of the Sliding Scale of Idealism vs. Cynicism. Justified since he is actually only a young child beneath his superhero exterior.
- What the Hell, Hero?: Delivers a fairly brutal one towards Superman after the latter destroyed Lexor City during their fight. He also announces his resignation from the Justice League in the same speech. Superman is crushed.
Hawkman (Carter Hall)
Hawkman, also known as the archaeologist Carter Hall, is a man who claims that he is the reincarnation of an ancient Thanagarian who became emperor of Egypt and that Shayera's past life was his lover. Well intentioned, but a bit creepy given his obsessive attitude. He dons a pair of artificial wings and Thanagarian battle armor, apparently fighting crime.
- Adaptational Nice Guy: The comic version of Hawkman is an extremely aggressive, bloodthirsty brute of a man, though still heroic. This version is quite mellow and friendly.
- Adventure Archaeologist: His day job is exploring old tombs and evading traps.
- Ancient Astronauts: His past life landed in Egypt, taught them agriculture and started conquering the nearby lands to bring civilization. Without them, Earth probably would not be as advanced as it is today.
- Badass Bookworm: He's just an archaeologist, but when he touches the Absorbicron he decides he's the reincarnation of a Thanagarian, builds some artificial wings for himself and begins fighting crime. He even seems to be pretty good at it, capturing a magician who was giving John trouble.
- The Cloud Cuckoolander Was Right: It is mentioned that he lost much of his credibility in the archaeology field when he began proclaiming his Thanagarian Ancient Astronauts theory and even Hawkgirl thinks he is delusional when he insists that they are the reincarnations of the ancient Thanagarians. Then in "Ancient History", the Shadow Thief reveals that his claims were right all along.
- Crazy Jealous Guy: Subverted. When Shadow Thief tells him to kill his rival Green Lantern, it looks as though he's going to do it. However, Carter simply uses the axe he was given to free John from his restraints.
- Decomposite Character: Turns out he is not Shayera's destined lover reincarnated, GL is. Shayera and Hawkman were married in a previous life and were fond of eachother, but Shayera's true (and secret) love was John (who was also Hawkman's best friend, ouch).
- Driven to Suicide: When Katar Hol realized his advisor has poisoned Past Shayera and John, he committed suicide himself out of grief.
- Flight: He wears a pair of artificial wings strapped to his chest that allow him to fly.
- I Want My Beloved to Be Happy: After discovering the true history between Katar Hol, Chay-Ara Hol, and Bashari, he quickly apologizes to Shayera and leaves, realizing that she is destined to be together with Green Lantern.
- Meaningful Rename: He used to be a man named Joseph Gardner, but when an ancient ship's log showed him his past lives he legally changed his name to Carter Hall, which sounds almost the same as Katar Hol.
- Nice Guy: He may be a stalker, but he actually is a good guy and genuinely heroic.
- Reincarnation: He's probably the reincarnation of an ancient Thananagarian police officer.
- Romantic Runner-Up: A nice guy, but Shayera is also interested in John Stewart. When he learns how the relationship of their past lives ended, he leaves peacefully, telling her he has no intention of getting in their way.
- Reincarnation Romance: Subverted. It's strongly implied that he's right about his past life with Shayera, but the relationship had already fallen apart due to Katar Hol's refusal for intimacy.
- Stalking Is Love: Though he tends to creep some people out, he genuinely loves Shayera and wants what is best for her. When he realizes he's making her uncomfortable he gracefully backs off until she feels she's ready. When it becomes clear she never will be, he gives up. For her part, she ignores that he's an obvious stalker until he starts babbling about reincarnation and seems to think he's at least somewhat attractive.
- Winged Humanoid: With a pair of artificially constructed wings.
Deadman (Boston Brand)
Deadman, real name Boston Brand, was a wandering spirit.
- Alliterative Name: Boston Brand.
- Back from the Dead: Boston Brand was a circus performer who was murdered during a circus act, and consequently forced to dwell in the Earthly realm as a ghost.
- Barred from the Afterlife: Kinda. He can visit, but he never stick around.
- Demonic Possession: Deadman is capable of possessing any mortal being; upon which he could completely control their actions and be in possession of their memories and powers, while they retain no recollection of the happening.
- Hollywood New England: Well, his name is Boston and he certainly sports the accent.
- Intangibility: As ghost, Deadman can also pass through physical objects.
- Invisible to Normals: He cannot be visibly perceived by other human beings.
- Meaningful Name: As a ghost, you don't get any more meaningful than "Deadman".
- My God, What Have I Done?: When Devil Ray attempts to shoot Wonder Woman, he quickly possesses Batman, picks up a gun, and shoots Devil Ray, accidentally knocking the latter into electrical wires and killing him. This action is rather traumatic for both him and Batman.
- Roaring Rampage of Revenge: After the Legion destroys the Buddhist Temple he was training at and kills the Master.
- Thou Shalt Not Kill: His memory of his Master's teachings convince him to spare Devil Ray's life. He later unintentionally does it anyway.
- You Killed My Father: His motivation for getting revenge on the Legion of Doom and Devil Ray specifically.
Huntress (Helena Bertinelli)
Formerly the sheltered daughter of a Mob boss, she became a vigilante in response to his betrayal and murder. She was inducted along with all the other heroes in the first episode of Unlimited, but after she violated the League's rule about attempting to murder villains, she became a Sixth Ranger who helped out her friends in the League.
- Adaptational Nice Guy: While still an Anti-Hero, she's more heroic here than in the comics, especially after she resolves her issues with Mandragora.
- All Women Are Lustful: She almost always interacts with The Question in a very suggestive way, and some of those interactions tend to imply sexual fantasies.
- Anti-Hero: A little too 'anti' for the League, especially since her first major appearance involves her trying to murder Mandragora while sleeping in his home. She's half Type III, half Type V.
- Automatic Crossbows: She carried an automatic miniature crossbow that she wielded with incredible ease and accuracy, as well as a retractable bo staff and other equipment used to bypass security measures.
- Badass Biker: Her preferred method of transportation.
- Badass Normal: She is a world class athlete, gymnast and martial artist, capable of disarming and defeating multiple armed opponents (however, she was slightly less skilled than Black Canary).
- Bare Your Midriff: Her costume shows off her toned stomach.
- Battle Couple: With the Question. They casually discuss dating plans while kicking butt.
- Blood Knight: After helping Black Canary shut down Roulette's underground metahuman brawl operation, she goads the former into going a few rounds in the cage themselves, to see who's the better fighter.
- Dark and Troubled Past: Helena Bertinelli was the daughter of Mafia crime boss and mobster Franco Bertinelli. As a child, she saw her mother and father murdered by Steven Mandragora, who lusted for power. This event sparked her desire for revenge as, years later in her adult life, she would train herself to become the costumed vigilante known as the Huntress.
- Dark Is Not Evil: Her vigilante costume is mostly black and purple and while she's an Anti-Hero, she's still on the side of good.
- Deadpan Snarker: Constantly makes snide and sarcastic remarks even on the people she works with, or otherwise needs the help of.
- Early Installment Character-Design Difference: In earlier episodes when she was just The Cameo, her design was different (ex. white eyes instead of showing her eyes).
- The Friend Nobody Likes: A trait she shares with the Question. She has a considerably poor reputation among members of the League with the last straw involving Mandragora resulting in her membership being revoked. Even Black Canary, probably her closest friend besides the Question, mainly gets into physical fights with her.
- Lonely Together: Implied to be the bedrock of her relationship with the Question. He was the only one who tried to help her resolve her personal vendettas and actually treats her respectfully, mainly because he's also seen as a crazed loner Anti-Hero who doesn't play nice with other members of the League.
- Mafia Princess: Was one of these — and did not know. She finds out the hard way.
- Most Common Super Power: She has a very large bust.
- Ms. Fanservice: Huntress is a very beautiful woman who wears a costume that highlights her voluptuous yet toned body, toned stomach, buxom breasts, long legs, and nice rear end. She doesn't get the amount of in-universe attention that Wonder Woman or Black Canary do, but the camera does develop Male Gaze when she's in an episode.
- Official Couple: Huntress and Question became lovers, and also an unofficial team.
- Strong Girl, Smart Guy: With the Question, as she acts as the muscle while he mainly does detective work.
- Thou Shalt Not Kill: Tried to avert this, which is why J'onn kicks her out of the League.
- Tsundere: Towards the Question. Between snarking at his sleuthing tendencies, she's also kindly to him in tender moments, even calling him "Baby".
- Violently Protective Girlfriend: Huntress is this for Question. If he's working at a console, you can expect her brutally beating guards into unconsciousness in his defense. When the Question was tortured by Cadmus, she nearly outright murdered his torturer until she was recalled by Superman.
- Vitriolic Best Buds: Originally she regarded Black Canary as an interfering obstacle; after Canary helped with the Mandragora capture, they reached a rapport.
- Voiced by: Scott Patterson
A federal agent who often assists the Justice League. He was assigned to provide protection to mob boss Steven Mandagora, who supposedly wanted to leave organized crime, until it was revealed that he was simply biding time to secure to safe passage of his son into the United States. By the final season, he's made an official liaison of the Justice League to the US.
- Friend on the Force: Given how government workers and agents are usually distrustful of the League, it's refreshing to see that he has little problem with them. So long as they don't do what like. Like hitting mob bosses under witness protection, for example.
- Punny Name: King Faraday is a play on "king for a day". Of course, he gets to keep that name forever.
- Shout-Out: Uses the line, "goldbricking yahoos" in "To Another Shore", which is a Nick Fury turn of phrase.
- Why Do You Keep Changing Jobs?: Good luck nailing down what agency he works for. He switches from witness protection (US Marshals) to bodyguarding the Vice President (Secret Service) when not being the JLA's liaison. To be fair, this is a quirk of government agencies in the comics, like APES and the CBI.
- Voiced by: Kim Mai Guest
A reporter in Central City.
- First Girl Wins: As far as we know, she's the Flash's first real romance and claims this to Giganta, who's been trying to date Flash ever since the ending of Unlimited. Between the two girls, Flash sticks with Linda.
- Is This Thing Still On?: Thinking that the camera is off, she talks to her camerawoman about how Flash is "like, the entire track team at once". Only after she says that does her camerawoman tell her that the camera was still running, causing her to facepalm.
- Two-Person Love Triangle: According to the Red Justice young reader's book, Wally tried dating her, but she broke up with him when she thought that he wasn't committal.
- Unwitting Instigator of Doom: She brings a pocket mirror to the Flash Museum so she can check her makeup. She wasn't counting on Mirror Master and the other Flash rogues to use it to get the drop on everyone through it.
Green Lantern (Hal Jordan)
- Voiced by: Adam Baldwin
In another life, Hal Jordan would have been the Green Lantern that joined the Justice League. During the crisis caused by Chronos's tampering with the timeline, he briefly appeared in place of John Stewart.
- Reasonable Authority Figure: While trying to get information about Chronos's whereabouts from his wife, he assured her that the League will try their best not to hurt her husband.