%% Per wiki policy, name of the trope should never be spoiler-tagged on character sheets.

This character sheet is for the [[LongRunners long-running]] MedicalDrama ''Series/{{ER}}''.

''Warning! Major spoilers ahead''.

[[folder:Mark Greene]]
!!'''Mark Greene'''
->'''Played By''': Anthony Edwards

* AmbiguouslyJewish:
** One of his parents was Jewish and he knows a bit of Yiddish and some Jewish prayer. Other than that, he doesn't display any Jewish mannerisms and Anthony Edwards himself is not Jewish.
** He actually describes himself as the son of "a lapsed Catholic and an agnostic Jew."
* BackForTheFinale: While he doesn't appear in the final episode, a flashback episode midway through the last season showing Catherine's first encounter with County Hospital reveals that he treated her son (sadly, the son was already terminally ill). The event clearly takes place shortly before his death, which adds a further bit of melancholy.
* BadassBeard: Grew one at least twice. The first time, in Season 2, it was to impress women (Mark also tried wearing contacts). The second time he grew one when [[BeardOfSorrow his mother was hospitalised]]. Ironically, when his mother actually died he was completely clean shaven.
* BetaCouple: Mark and Elizabeth's relationship has aspects of this--they don't get together until after Doug leaves and the writers clearly needed a couple to replace Doug and Carol. While it is at the forefront (mainly because Mark was the de facto main character), their relationship is relatively problem free and problems only really arise when Elizabeth gives birth and Rachel comes to live with them.
* BettyAndVeronica: In the first three seasons, he's the Archie for Susan's Betty and Jen's Veronica: Susan's a competent doctor and one of Mark's best friends, while Jen's his high school sweetheart-turned-wife who ends their marriage by [[YourCheatingHeart cheating on him]] and leaving him for the other man.
* BirdsOfAFeather: Mark and Susan.
* BittersweetEnding: Despite dying of cancer, in the very least he got to spend his last moments with his family and in an island paradise. His doctor also advises him that he spent the extra year when the cancer seemed to be cured very well, getting married and seeing another child being born.
* BookEnds: When his father died Mark spent his last days repairing their relationship. When he was dying he pulled Rachel out of school so that he could spend his last moments with her and try to repair their relationship.
* ButtMonkey: Eight seasons, and something crappy happened to him in every one of them.
* TheCasanova: Amazingly, despite never having slept with anyone other than his wife, Mark manages to pick it up after his divorce and Susan's leaving. Unfortunately [[CasanovaWannabe he's not so good at the finer aspects of being a player]], scheduling three dates on the same night that all the participants find out about (Nina, the psych Attending, eventually agrees to go out with him).
* ChronicBackstabbingDisorder: His position of authority puts him in difficult standing with his friends, and often times had to make tough choices involving them. Unlike Kerry, though, he rarely, if ever, outright stabbed anyone in the back.
* CommonalityConnection: He describes his beating to Mobalage, getting him to open up about his own torture and saving him from deportation.
* DeadpanSnarker: Develops quite a sense of humour when he was diagnosed with a brain tumour.
* GenerationXerox: His eldest daughter Rachel follows his footsteps and applies to medical school in the GrandFinale.
* GrumpyBear: Occasionally.
* TheHero
* TheHeroDies
* HeroicBSOD: He suffers these repeatedly--after mishandling a childbirth, resulting in the mother's death, after his wife leaves him for another man, after Susan leaves him before they can even have a relationship, after being beaten up (losing Susan made him feel bad, being beaten up made him feel worse), a small one after his father dies and after learning that his brain tumor has returned and is now inoperable.
* HeterosexualLifePartners: With Doug. Their friendship is complicated by Mark's role as an authority figure and his boss.
* HollywoodAtheist: Averted. In one deleted scene from "On the Beach", Mark says outright that he doesn't believe in God. But it doesn't really affect his characterization otherwise.
* {{Hypocrite}}:
** Frequently chastised Doug for getting too personally involved with cases and bending/breaking the rules to help his patients when he himself often did the same thing.
** Blasted Kerry for not wanting to report her Alzheimer's stricken mentor. A year later, when he himself suffered cognitive impairment following brain surgery and chemotherapy, blasted Kerry for reporting ''him''.
* IllBoy
* IWantMyBelovedToBeHappy: In a deleted scene for "On the Beach", Mark tells Elizabeth he has absolutely no problem with the idea of her getting re-married again, saying that she deserves to be happy and that Ella deserves a father. Elizabeth is very resistant to the idea and tells Mark he should stop talking this way.
* IWasQuiteALooker: The now-balding Mark tells Rachel that he used to have hair down to his shoulders. Anyone who's seen Anthony Edwards in ''Film/FastTimesAtRidgemontHigh'' can vouch for this.
* MagneticHero: Is ''very'' respected by his colleagues. Even [[IWorkAlone lone wolf]] Benton sometimes goes to Mark for advice. Works posthumously too--in the final season, Catherine agrees to give Carter work in the ER whilst he's in Chicago because she learned that Mark was one of his teachers (Mark treated her son).
* MeaningfulName: Green is the color of medicine.
* OfficialCouple: With Elizabeth.
* OppositesAttract: Mark and Elizabeth show shades of this. While they get along very well their personalities are quite different. Mark is rather soft and more patient, more willing to understand people and to give them second chances. Elizabeth is a lot tougher and a lot harsher. Their respective personality differences become apparent when Ella overdoses on Rachel's ecstasy, Elizabeth wants Mark to call the police and wants Rachel out of the house (and tells her as much), whereas Mark (probably because Rachel is his daughter) just wants to work things out and to try and help his daughter. Elizabeth is also more career-oriented, taking up Romano's offer of the Associate Chief of Surgery position despite suspecting ulterior motives, whereas Mark is content just to run the ER.
* ParentalNeglect: Claims that, as a teenager, he started acting out in frustration because his father was never around. Mark starts to fear, even before his tumour recurs, that Rachel's acting out is because he made the same mistakes.
* ParentalSubstitute: For Carter. Mark gives Carter the nurturing encouragement that he doesn't get from Benton, and they fill a need in each other's lives, as Mark doesn't get to see his daughter very often and Carter's parents are often on vacation somewhere.
* PosthumousCharacter: "On the Beach" is somewhat non-linear, in that it aired after "The Letter", in which the ER staff are notified that he has died, and yet it takes place immediately after "Orion in the Sky" (Mark's last day), during "Brothers and Sisters" (Elizabeth goes to Hawaii to be with Mark) and between "The Letter" (Mark's death obviously happened before the episode, but Mark's funeral happened afterwards). Meanwhile, the final season episode that featured his "return" was actually a flashback to his last days at the hospital.
* PrecisionFStrike: In quite a shocking moment for TV at the time, he gives an uncensored "Shit!" after suddenly losing his balance upon getting out of bed, indicating just how much his days are numbered.
* PronounTrouble: After he undergoes surgery to remove his brain tumor, he starts mixing up "he" and "she" in mid-tirade. It gets to the point where Kerry orders competency testing.
* TheSouthpaw: When his tumour starts to worsen, he starts using his left hand.
* TeamDad: To many, but especially to Carter.
* TookALevelInJerkass:
** Starting in Season 3 after Susan leaves, beginning with him violating Jeanie's privacy by snooping into her files to find out her HIV status. It kicks into high gear after he's beaten up--he becomes cynical and unpleasant and while arguably he deals with some patients the way they should be dealt with, most of the time he just comes off as a total jerk. Thankfully, he gets better after that season.
** After his first tumour, Mark begins to suffer personality changes. While not as bad as when he got beaten up, Susan reprimands him at one point for being so harsh with patients and tells him that he isn't quite the kind and caring Mark she used to know.
* UnexpectedVirgin: He admits to Doug that he nervous about his first date since his divorce because his ex-wife is the only woman he's ever slept with.
* UnresolvedSexualTension: With Susan, ultimately leading to an averted RaceForYourLove scenario. A deleted scene from "Orion in the Sky" (Mark's last day at County) has Mark and Susan talking about what happened at Union Station five years later. Susan obliquely asks Mark if she hadn't moved away, they'd be together. Mark then mentions his grandfather and how he used to say that everything happens for a reason, then he says it was just one of those things that sounded even stupider as he got older.
* VigilanteExecution: He not only refused to help the man who threatened to kill him and his family, he taunted him as he died by holding up the shock paddles in front him. He never suffered any legal ramifications for doing so.
* YankTheDogsChain: Anspaugh, at one point, promises to offer Mark a tenured position at the hospital within three years if he agrees to stay on staff and not join a NASA program. This means that Mark could get tenure as early as 2002. Mark died in 2002.
* YourDaysAreNumbered

[[folder:Doug Ross]]
!!'''Douglas "Doug" Ross'''
->'''Played By''': Creator/GeorgeClooney

* AbusiveParents: A BerserkButton for him, no doubt because his father was one of these. [[FridgeBrilliance This is probably why]] he became a pediatrician in the first place.
* AnguishedDeclarationOfLove: He delivers two to Carol at different points--first when he races to her and Tag's engagement party in "The Gift", then again at the end of "The Storm, Part 2".
* BreakoutCharacter
* BrokenPedestal: Becomes this to the son of a woman he dates in Season 1 after he inevitably cheats on her and ruins the relationship.
* BunnyEarsLawyer: His first appearance has him coming into work drunk and talking about his sexual conquests, setting the viewer up for further instances of Doug breaking the rules and ignoring hospital procedure. During Season 2, the Chief Attending of the pediatric ward gets into arguments with both Morgenstern and Mark about renewing his fellowship, with Mark arguing in Doug's favour by saying that he's a good doctor. Doug, from then on, manages to keep his job through pure, unquestionable excellence, despite Mark and Kerry's frustration with him.
* TheBusCameBack: Twice. First for an uncredited cameo in Season 6, the second time in Season 15.
* CallingTheOldManOut: Inverted. He tries to blame his abusive father for his horrible adulthood, but his father informs him that "[[JerkassHasAPoint You're 34 years old. How you live your life is your decision]]."
* TheCasanova
* ChickMagnet
* ChuckCunninghamSyndrome: Neither he nor Carol appear at Mark's funeral--without any explanation as to why--even though they were best friends. He and Carol also didn't appear at his wedding to Elizabeth a season earlier, although that can be explained away, since a storm grounded all of Mark and Elizabeth's out-of-state guests, including Mark's eldest daughter Rachel.
* DisappearedDad: Had one, may have been one to his twice-mentioned son.
* FreudianExcuse: His experiences with an abusive father explains much of his behavior, bad ''and'' good.
* FriendToAllChildren: Consistently.
* FunctionalAddict: While he clearly has a drinking problem--he shows up drunk at the hospital in the {{Pilot}} and Mark's reaction indicates that this isn't the first time this has happened--it never seems to affect his work or cause any other mishaps for him. Even when he gets his act together, he never declares himself to be an alcoholic, and given that he seems less inclined to drink when things are going well for him, he may just be very inclined to DrowningMySorrows.
* HappilyMarried: To Carol.
* HeadbuttingHeroes: He's dedicated to the welfare of his patients, consequences be damned, which might be admirable...if he ever recognized that those consequences sometimes land on people other than him. Even Mark eventually reaches a point where he just can't deal with Doug's thoughtlessness anymore.
* HeelRealization: After one of his random one-night-stands dies of an overdose and it really begins to sink in just how much he's screwed up his life.
* HeterosexualLifePartners: Mark and Doug are best friends, and seem to spend a lot of time together. As Doug is such a "cowboy" (as some of the other doctors put it), Mark's position of authority often complicates their friendship. However, Mark, more often than not, is perfectly willing to advocate for Doug, and during Season 2 he campaigns to keep Doug at the hospital despite the fact that the Pediatric Chief Attending wants him gone, stating that Doug's a good doctor.
* HollywoodAtheist: Claims to be Pagan, but demonstrates contempt for religion (specifically Christianity). He crosses himself in one episode which suggests he may have grown up Catholic, only to lose his faith later on.
* LadykillerInLove: He's established as the hospital stud in the pilot. But in that same episode, it's also poignantly obvious that he's desperately in love in Carol.
* TheLancer
* LovableTraitor: Occasionally. His loyalty to children above everything and everyone else is both his greatest strength and greatest weakness, and he will do ''anything'', including lie to and double-cross friends, to protect them. It almost gets him fired, until his rescue of a drowning child in "Hell and High Water" forces the hospital to reconsider.
* MrFanservice
* OfficialCouple: With Carol.
* OneTrueLove: Carol. Doug mentions to Mark when they got back together that his relationship with Carol was the only one that felt "right." In a Season 1 episode, even his then-girlfriend notes this.
* PutOnABus: Midway through Season 5.
* ReallyGetsAround: Until Season 3, where he tries and succeeds in changing his ways.
* RedemptionInTheRain: He receives one in "Hell and High Water", when he emerges from a flooded area with the kid he's been trying to save, after the previous few episodes having shown him going down a slippery slope.
* ScrewTheRulesImDoingWhatsRight: Deconstructed. This was essentially his motto but ultimately became his downfall when actions ended up jeopardizing the careers of himself and others.
* SexGod: Dialogue from former girlfriends make it quite clear he's this.
* TallDarkAndHandsome
* TroubledButCute
* TheUnseen: He's mentioned in Season 6 as having come to Chicago to visit his baby daughters and to ask Carol again to move to Seattle with him. The viewer doesn't see his visit or his and Carol's exchange.

[[folder:Susan Lewis]]
!!'''Susan Lewis'''
->'''Played By''': Sherry Stringfield

* TheBusCameBack: Returned as a regular in Season 8 and stayed until the Season 12 premiere. She also came BackForTheFinale.
* CharacterSignatureSong: "Blackbird" by Music/TheBeatles. In Season 2 this trope is very much played for drama as the song becomes symbolic of the bond between her and her niece Little Suzy.
* ChastityCouple: With Carter. Susan mentions in "Secrets and Lies" that they had yet to have sex, and she breaks up with him after realizing that he was obsessed with Abby and didn't feel that way about her.
* DeadpanSnarker: Especially after her return.
-->'''Susan''': You're late.\\
'''Luka''': Blame my alarm clock.\\
'''Susan''': Oh, yeah? What's her name?
* FoolishSiblingResponsibleSibling: Was the latter to her drug-addicted older sister.
* HairOfGoldHeartOfGold: Dark blonde rather, but the trope still applies.
* HeroicBSOD: Had to see a therapist after she was forced to give her niece (who she was raising as her own daughter) back to her sister. In an earlier season, she also struggles with confidence issues after being blamed for a patient's death.
* NoodleIncident: After her return. It seems like the viewer missed a few things, including her engagement to a real-life cowboy.
* ParentalNeglect: Her mother is rather aloof and self-absorbed and it's implied that Susan and her sister pretty much had to take care of themselves growing up, leading to the latter's problems. Her father initially doesn't seem to be much better, although he eventually steps up and offers to take care of little Susie at night whilst Susan goes to work.
* PutOnABus: Midway through Season 3 and after the Season 12 premiere.
* TheSouthpaw
* TheUnfavorite: Was also inexplicably this to her drug-addicted older sister, despite being a doctor. To their credit, as cited above, after her sister abandons the baby, their parents realize their mistake and pitch in to help.
* UnresolvedSexualTension:
** With Mark. According to Carol, Susan absolutely wanted Mark to come to Maui with her, but was afraid that he would be freaked out by the invitation. When he gets sick Susan takes care of him, which makes Carter (who didn't know Mark was sick again) rather jealous.
** Some with Carter, when she left the first time. When she comes back, they get together but the relationship more-or-less fizzles because of Carter's obsession with Abby.

[[folder:John Carter]]
!!'''John Truman Carter III'''
->'''Played By''': Creator/NoahWyle

* AbusiveParents: Of the severely emotionally neglectful type, to the point where not even him being nearly ''stabbed to death'' could make them cut short their vacation plans to be by his side. However, their FreudianExcuse of their grief for his younger brother makes them slightly more sympathetic than most examples of this trope.
* AudienceSurrogate: Started out as this, being the only rookie among the more experienced staff.
* AuthorAvatar: Of Creator/MichaelCrichton, who based the {{Pilot}} on his time as a medical student.
* BeardOfSorrow: He had one after his stint in rehab. He shaved it off on the plane back to Chicago.
* BreakoutCharacter: Was generally quite a popular character throughout the show. Helped largely by his relative affability, his natural development, and overall longevity. Noah Wyle received more Emmy nominations than any member of the cast outside of Julianna Margulies.
* TheBusCameBack: In Season 12 for four episodes. He also came BackForTheFinale.
* ButtMonkey: He suffers through a lot of pain and humiliation. Some of it is PlayedForLaughs, but there are also a fair number of darker moments that [[HeroicBSOD take a toll on him]].
* TheCasanova: He's pretty much able to get any girl he wants, although he rarely seems to use this ability, instead going for the "maybe we should be friends first" approach.
* CharacterDevelopment: As prominent an example as the show could give. He starts out the first few seasons as a TagalongKid, learning how to function in the hospital setting under Benton's tutelage while also figuring out what role he wants to play as a doctor (eventually switching from surgery to emergency medicine). He then grows comfortable at County, gradually settling into the role of TheLancer for Mark after Doug left. When both Mark and Benton left at the end of Season 8, it is explicitly noted that he's become TheHero, a role that he carries throughout the remainder of his time on the show. By the time he is ready to leave, it is clear that the rest of the staff thinks of him as the BigGood, something made more apparent when he returns in the final season and a delighted Morris explains to his medical students and interns that Carter's "a legend."
* ChickMagnet: How many girlfriends did he have during the entire show, again?
* DramaticallyMissingThePoint: When some of the hospital staff stage an intervention against Carter he challenges them to name one instance of him endangering patients' lives. Jing-Mei mentions how he sent a patient into anaphylactic shock by giving her a drug she told him she was allergic to. Carter then retorts that she almost killed a man by leaving a guide wire in his chest. Firstly, said incident took place practically six years ago, when Jing-Mei was a medical student. Secondly, that incident was no indicator that Jing-Mei was starting to fall apart.
* HeroicBSOD: Carter goes through a lot of trauma on the show, like most main cast members. The fact that he was the longest-running character meant that they were even more frequent, especially as it resulted in him seeing friends and family die around him. They include:
** The death of his friend Dennis Gant in Season 3 (heavily implied to be suicide due to Benton's rigid treatment of him). Carter spends much of the following episode going over how much more supportive he could have been when it was clear that Gant was struggling.
** The murder of Lucy Knight in Season 6. The ER had admitted a schizophrenic patient that Lucy had expressed concern over, only for Carter to brush her off. The patient then ended up stabbing them both, with Carter eventually surviving while Lucy succumbed to complications in surgery. The aftermath provides enough trauma to send Carter over the edge and into drug addiction.
** The death of his grandmother in Season 9. As he was dating Abby at the time, the issue becomes exacerbated when Abby has to help take care of her bipolar brother Eric (who shows up uninvited to the funeral and falls into the open grave). This leads to Carter feeling alone in his time of grief and partially results in his decision to join Luka in the Congo.
** The stillborn birth of his son in Season 10 crushes Carter immensely (he is shown breaking down in his father's arms immediately afterward) and casts a huge shadow on his relationship with Kem. Even by the time of the series finale 5 years later, it's left ambiguous as to whether or not their relationship can fully recover.
* {{Hypocrite}}: Lectures Lucy about taking amphetamines for [=ADHD=], as it's typically a pediatric illness and she's in her early 20s. She irritatedly tells him that he's not her physician and that it isn't any of his business. A year later, when Mark asks him what pain medication he's on, he gives a similar answer. So it's okay for him to butt into Lucy's personal life, but no one can do that to him?
* LastNameBasis: 15 years and you could probably count on one hand the number of times he was called by his first name, rather than his last. It's given a LampshadeHanging in an early Season 1 episode, when he and Susan share a conversation and she admits that calling him "John" doesn't feel right, probably because Carter is [[AwesomeMcCoolName a cooler name]]. Notably, Kerry, Lucy and Jing-Mei are the only regular characters who ever called him "John", even if only on occasion.
* LikesOlderWomen: A good portion of his love interests were slightly (5-6 years) older than him, with Abby Keaton maxing it out at 16 years his senior. Jing-Mei--who herself was several years older than him and who he enjoyed a mild flirtation with--makes note of this and accuses him of "liking" Kerry; Carter counters that he simply doesn't ''dislike'' her the way everyone else does. He does have a flirtation with Lucy (approximately 5 years his junior) but is quickly able to cut it off before it can go anywhere more than a kiss when he notes how unprofessional it would be. Ultimately {{Averted|Trope}} with his final main love interest, Kem, who is roughly the same age as him.
* MrFanservice
* NaiveNewcomer: He started out as this, being a third-year medical student as opposed to the more experienced staff.
* NiceGuysFinishLast: It took him ''forever'' to become an Attending, and only was made Chief Resident after Jing-Mei was fired. It was even implied that once his residency was over, Kerry had no intention of hiring him, and only did so because of a shortage of Attendings. And this is ''after'' being forced to repeat his first year of residency due to switching specialties and then being told he is repeating his third year thanks to his drug issues.
* NonIdleRich: Aside from going to medical school rather than joining the family business and living off their fortune, Carter transfers to Emergency Medicine just to spend more time getting to know his patients. When Kerry says they might not have space in the budget for him, he nonchalantly says he doesn't need a salary, which surprises her. Throughout the entire series, particularly in the finale, he is repeatedly shown to use the family money for charitable interests.
* TheNotLoveInterest:
** To Jing-Mei. Despite a mutual attraction, occasional flirtation and them being one of the show's {{Fan Preferred Couple}}s, it never goes beyond a close friendship.
** Also to Maggie Doyle. They hit it off and he's clearly attracted to her...but [[IncompatibleOrientation she's gay]].
* OnlyOneName: PlayedWith. Some people did refer to him as "John", such as Kerry, Lucy and Jing-Mei, but virtually everyone else called him "Carter". Jerry {{Lampshade|Hanging}}d this once:
-->'''Jerry:''' He's just...''Carter''.
* PutOnABus: After Season 11.
* RapeAsBackstory: During a sequence where several others are discussing when they lost their virginity, he claims he was 11 and that his partner was a 25 year old maid. No one, including him, seemed to regard this as child molestation and it's practically a BigLippedAlligatorMoment--never mentioned before, shows no signs of affecting him, and was never mentioned again.
* SecretlyWealthy: Everyone was stunned when he was revealed to be from a wealthy family, although there were subtle hints beforehand, such as Carter's tailored lab coat in the {{Pilot}} and Benton's mother claiming that Carter's family might have once owned Benton's family when Carter admits to having relatives in Tennessee.
* UnresolvedSexualTension: With several people, but most obviously with Anna.
* TheWisePrince
* YouAreInCommandNow: When Mark leaves, he instructs Carter to "set the tone", just as Morgenstern had told him in the pilot. {{Lampshade|Hanging}}d by Kerry afterwards:
-->'''Kerry''': Mark's gone. [[LeaningOnTheFourthWall That means you've been here longer than any other doctor. People will look at you to step in and fill the void]].\\
'''Carter''': ''({{Beat}})'' Big void.\\
'''Kerry''': Yes, it is.

[[folder:Peter Benton]]
!!'''Peter Benton'''
->'''Played By''': Eriq La Salle

* AngryBlackMan: To an extent. He's relentless in his abuse of Dennis Gant because he claims Gant, as a black man, has to work twice as hard to prove he's just as good as his white counterparts. Benton is also uncomfortable with dating Elizabeth because she's white (largely because he's concerned about what his family might think) and resents Cleo's attempts to prove herself by being enraged at what she sees as prejudice, claiming that as a half-white woman she knows nothing about real prejudice.
* BadassBeard
* BigBrotherMentor: To Carter, although he acts more like an AloofBigBrother than the caring, nurturing kind.
* BlackAndNerdy
* TheBusCameBack
* DaddyDNATest: Twice. The first time Carla claims Benton may not be Reese's father. He goes as far as swabbing both him and Reese before telling himself and Carla that it's not important. The second time Roger challenges Benton's paternity (something Carla couldn't have done, as she put Benton's name on the birth certificate) and forces him to take a test. As it turns out, Reese's isn't Benton's biological son.
* DrJerk: He's über-driven, and incredibly unforgiving of anyone he felt didn't have the same level of drive that he did.
* EvenBadMenLoveTheirMamas: Is gruff and abrasive, but adores his mother. His complete denial of how ill and frail she's becoming is in stark contrast to his skills as a physician and the scene where he breaks down over her death is one of the saddest of Season 1.
* ExtremeDoormat: Falls into this trope a lot, which is a surprise given his personality. Many of the biggest problems in his life result from his need to please or protect others who are taking advantage of him.
* FamilyVersusCareer: Leaves County and emergency medicine for what looks like a [[HospitalParadiso rather dull clinic job]] so that he can have better work hours and get custody of his son.
* GrumpyBear
* HappilyMarried: To Cleo.
* HeadbuttingHeroes: He's a very talented surgeon, but his abrasive personality and arrogance make him hard to work with. Notably, the entire surgical service and the ER staff practically refuse to work with him after he unnecessarily back-stabbed Doug (himself revered at this point for saving a drowning child in "Hell and High Water") over a missed diagnosis.
* HeroicBSOD: He has many. When his mother dies, when he nearly kills a baby in surgery, when Gant commits suicide, when his son is born prematurely with severe complications.
* HonorBeforeReason: Benton discovers Abby Keaton and Carter's relationship when he goes to her office to ask for a recommendation for a pediatric rotation. When she asks if he's threatening to tell TPTB about her and Carter (he's an intern and she's an Attending, so it's forbidden), his response?
-->"Dr. Keaton...if your recommendation is based on anything but my skills as a doctor, '''''I don't want it'''''."
* {{Hypocrite}}:
** When it comes to racial issues. He claims that Cleo, as a bi-racial woman, doesn't understand the medical needs of the black community, even though he had an affair with Jeanie, who was half-white and was hired by him to take care of his mother.
** When Carter transferred to Emergency Medicine. Benton told Carter that he should have come and talked to him instead of going straight to Anspaugh, even though when Carter actually came to Benton for advice on how to deal with Dale Edson (he falsified a chart, which is illegal) months earlier Benton simply blew him off.
** He also makes his son's stepfather out to be a jerk for seeking full custody of the boy, even though he's being just as rigid and stubborn throughout the whole custody battle. Plus, the other man tries to call a truce, offering him full custody as long as he gets to visit, which Benton rejects, only for the judge to make a virtually identical decision.
* JerkWithAHeartOfGold: Despite his brusque demeanor and often questionable bedside manner, he's very compassionate and wants the best for his patients.
* KickTheDog:
** In the {{Pilot}}, Carter starts to feel sick after seeing a patient with a severe knife wound. To add insult to injury, Benton says he didn't need Carter's help anyway. Fortunately Mark overhears this and goes to comfort Carter, telling him that Benton used to get sick all the time in med school.
** In Season 3, Benton just wouldn't give Dennis Gant a break (a fair amount of Benton's behavior was attributable to frustration at his fellowship in pediatric surgery going down the toilet). [[DrivenToSuicide Gant eventually killed himself]].
* MamasBabyPapasMaybe: He's originally presented as Reese's father, but when Carla wants to take Reese with her and Roger to Germany she suddenly claims that there was someone else. Benton eventually finds out that he isn't Reese's biological father, but he decides that he doesn't care and will be there for Reese no matter what. The fact that Reese acknowledges Benton as his father is the deciding factor in Benton's custody case against Roger.
* NotGoodWithPeople: He's a very talented surgeon and a very competent and studious doctor, but he often butts heads with his co-workers and he can't help but see the patients as anything other than people who need to be sliced and diced. This is more-or-less what flushes his chances at a fellowship in pediatric surgery down the toilet.
* OfficialCouple: With Cleo.
* PapaWolf: Most prominently to his son Reese, but also to Carter, his protege. He'd do anything for his son, ultimately quitting County so that he could spend more time with him, and when Carter was stabbed another patient almost died because Benton absolutely refused to leave Carter's side.
* TokenMinorityCouple: Him and Cleo--the sole reason she was even created was to give him an African-American love interest.
* TookALevelInCheerfulness: By the time Benton finally returns to the show in Season 15, he seems far more relaxed than he generally was during his time as a cast member. His banter with Carter and Elizabeth, in particular, is quite amicable. Spending all of those years maintaining happy relationships with both Cleo and Reese probably helped.
* UptightLovesWild: Deconstructed with him and Elizabeth. Aside from his uneasiness with their racial difference, in all likelihood the relationship would have failed anyway, as her vivacious, fun-loving personality was a stark contrast to his dour, aloof one.
* WhatTheHellHero:
** Abby Keaton gives this to him good and proper after he nearly kills an infant during surgery, blasting him for disregarding her instructions and not calling for help the minute he realized he was in over his head.
** Roger blasts him for trying to cut him out of Reese's life, when he's been in the boy's life almost as long as Benton has.
* WhereDaWhiteWomenAt: Averted. Despite their mutual attraction, he's very reluctant to date Elizabeth because she's white and even after they do get together, his persistent discomfort, as well as his chronic self-absorption, causes the relationship to fizzle very quickly.

[[folder:Carol Hathaway]]
!!'''Carol Hathaway'''
->'''Played By''': Julianna Margulies

* AscendedExtra: She was supposed to have been killed off in the {{Pilot}}--note that she's credited as a guest star, unlike the other original cast members--thanks to a suicide attempt, only to be revived thanks to positive test audience reaction. The result is that she was the show's heroine for the first six seasons and is the main cast's sole Emmy winner; she even {{Lampshade|Hanging}}d this in her acceptance speech, cracking that "I was dead this time last year, now look at me."
* AloofDarkHairedGirl
* BreakoutCharacter: Despite originally being envisioned as a one-off character who would die in the pilot, Carol immediately resonated with audiences and became one of the show's most popular characters. By the time of Susan's departure, she became the female lead of the show, and her coupling with Doug was easily the show's most high-profile romantic pairing. Additionally, Julianna Margulies was the only main cast member in the history of the show to win an Emmy award for her performance, and also received more nominations than any other performer (for all six years she was regularly on the show).
* TheBusCameBack
* ChuckCunninghamSyndrome: Doesn't appear at Mark's funeral--with zero explanation as to why--despite she and Doug being among his closest friends.
* DrivenToSuicide: In the pilot, she attempted suicide by OD'ing after her break-up with Doug. She recovered and moved forward with her life, and she and Doug reconciled a few years later.
* EmotionlessGirl: She spent the year after Doug's departure acting very distant and detached--there is a visible change in her demeanor as she leaves the hospital, races through the airport, and is reunited with him in Seattle.
* HappilyMarried: To Doug.
* HeroicBSOD: Has one after accidentally killing a patient (she gave him the wrong blood). Her refusal to let the incident be covered up or used as an excuse to punish the other nurses (who were all having a sick day in protest at the time) nearly costs her her job. She has another after Doug leaves.
* HonorBeforeReason: Not only does she refuse to let her fatal error be covered up or used to punish the other nurses, she insists on taking full responsibility--even though she could have easily and legitimately blamed the others--and on being reprimanded despite knowing that it could cost her her job and possibly even her nursing license.
* LawOfInverseFertility: When she and Doug are a happy couple, they struggle to conceive. When he resigns in disgrace and leaves Chicago, they conceive twins.
* OfficialCouple: With Doug.
* OneTrueLove: Doug. It's implied, but not explicitly stated, that Carol tried to kill herself in the pilot because of Doug's adulterous behaviour (she broke up with him over his many affairs, but then slept with him a month before she tried to kill herself). When he leaves for Seattle, she tells Mark that she can't remember a time she didn't love him. When she leaves Chicago to reunite with him, this is what she says to Luka about him:
-->"I've been in love with him since I was 23 years old. He's...he's everything to me. He's my life. I feel complete when I'm with him and I feel empty when we're apart. He's the father of my children...and '''''he's my soulmate'''''."
* PutOnABus: After Season 6.
* RavenHairIvorySkin
* TheSouthpaw

[[folder:Jeanie Boulet]]
!!'''Jeanie Boulet'''
->'''Played By''': Gloria Reuben

* AscendedExtra: She spent a year as a recurring character in Season 1 before being added to the main cast in Season 2.
* BlackAndNerdy
* TheBusCameBack: In Season 14.
* {{Claustrophobia}}: As seen when Kerry uses her as a test subject to test the efficacy of exercise in restoring broken circadian rhythms.
* DarkSkinnedRedhead: At times.
* EarnYourHappyEnding
* HeroicBSOD: Has one after finding out she's HIV positive.
* IllGirl: She's HIV positive. Then later she contracts Hepatitis C, although she eventually gets cured.
* MoralityPet: To Kerry. For a while, she was the only person who brought out Kerry's softer side.
* PutOnABus: Partway through Season 6.
* SympatheticAdulterer: Her husband cheats on her with many women, to the point where he contracts HIV in the process, which he passed to Jeanie. Her affair with Benton is therefore very understandable.

[[folder:Kerry Weaver]]
!!'''Kerry Weaver'''
->'''Played By''': Laura Innes

* AcademicAlphaBitch: A doctor equivalent. She's beautiful and brilliant, but has an ego the size of a small country and will stick a knife between anybody's shoulder blades to advance her own achievements and position in the hospital's hierarchy. She sarcastically refers to ''herself'' as an AlphaBitch in one episode.
* AdvertisedExtra: After she was made chief of staff.
* AllLesbiansWantKids
* AmbitionIsEvil. And how, given the number of deceitful things she does to either advance or maintain her career, in stark contrast to Mark, who is happy to remain an Attending.
* AscendedExtra: Spent a year as a recurring character in Season 2 before being advanced to the main cast in Season 3. Later DemotedToExtra.
* BaitAndSwitchTyrant
* BenevolentBoss: In the earlier seasons while serving as ER chief, she could be quite nice and helpful to her subordinates who were in need. Prime examples being in dealing with Jeanie's HIV status and Carol's pregnancy. [[TookALevelInJerkass She grew out of it]].
* BadassBureaucrat: While serving as ER chief, anyways. Its repeatedly shown that without her there to keep things on track the ER will quickly fall apart.
* BrokenBird: Despite her tough exterior there have been numerous instances where she has demonstrated herself to be really fragile underneath.
* BrokenPedestal: Frequently became this to the few people who liked and trusted her. In particular, Jing-Mei, who she mentored on her way to becoming Chief Resident before screwing her over to avoid taking any blame for a patient's death.
* TheBusCameBack
* ChronicBackstabbingDisorder: Her modus operandi was basically to pretend to be someone's friend/ally before screwing them over in order to save herself. This was so prevalent that one of her victims outright said "I knew she was capable of this, I just didn't think she'd do it to me."
* ControlFreak
* CunningLinguist: Knows Spanish, Swahili, and ASL.
* DefrostingIceQueen: Will often do something to prove to one of the the characters that she is genuinely a kind person underneath. For example, she demonstrates to Doug that she's actually very caring when it comes to children, she keeps Jeanie's HIV status a secret and then actively campaigns to keep her on staff when it's revealed, she lets Carter live in her basement and actually somewhat takes on the role of surrogate mother to him. However, she then follows up by doing something cold or horrible to them, making sure no one ever gets close to her.
* EvilRedhead
* FieryRedhead: Whatever her numerous flaws, no one could call her a wimp or a pushover.
* FriendToAllChildren: Consistently interacted very well with kids, despite her inability to get along with anyone else.
* {{Gayngst}}: During her relationship with Kim, where she was so terrified of anyone finding out that she would barely even speak to her while at work, and at the beginning of her relationship with Sandy, where she ran and hid to avoid being seen while out on a date.
* GeniusCripple
* HeadbuttingHeroes: She's a good doctor, but practically everyone in the ER has a contentious relationship with her because of her focus on unpopular administrative policies as well as a talent for patronizing and otherwise annoying the staff.
* HeelRealization: After Mark dies and she realizes that she made his life miserable by always trying to make everything into a competition when, "the man just wanted to do his job and go home."
* {{Hypocrite}}: Countless instances of her criticizing people for doing things she had done or would do herself. She also made sure anyone who screwed up was punished as severely as possible, while acting like her own mistakes were no big deal. A few standout examples:
** Made Doug's life hell and tried to sabotage Doug's career advancement because he was such a cowboy, and yet almost as soon as he leaves she tries to circumvent a standing DNR order (because she thought the woman was her biological mother)--then months later hounds Mark for doing the same thing, having the gall to insinuate that Mark isn't being objective because of the recent death of ''his'' mother, even though in this case, the patient had explicitly rescinded her DNR, telling Mark that she didn't want to die just yet.
** Pulls out all the stops to make sure Jing-Mei and Malucci are severely punished for their part in a patient's death--firing the latter and suspending the former, yet is just as vigilant in making sure that she herself incurs no punishment, even though as their supervisor, she bore the ultimate responsibility.
** Pleads with her ex-lover Kim to fight Romano's efforts at firing her (because she's a lesbian)--while she herself continues to keep her mouth shut.
** Hemmed and hawed about reporting her Alzheimer's stricken mentor, but instantly reported Mark for his impairment.
* HypocriteHasAPoint: After a patient dies because he slept with a paramedic on duty, Malucci is fired by Kerry for irresponsibility. Although Kerry, as Malucci's supervisor, should have kept a closer eye on him, Malucci's behavior is indeed completely unbefitting of that of a doctor.
* InferioritySuperiorityComplex: Her constant strive to be promoted at work as well as her general tendency to overachieve and over-do things is probably a reaction to her congenital hip dysplasia and her mistaken belief that her birth mother gave her up because of it. As a result, Kerry constantly tries to prove that she's not inferior by trying to be better at her job than everyone else.
* InspectorJavert: There were times when she was downright fanatical in her insistence that people adhere to rules and policy, not believing in making the slightest of allowances for any reason.
* ItsAllAboutMe: Had a bad habit of this whenever things got tough. When her girlfriend is investigated for sexually harassing/assaulting a patient, the woman comes to her, clearly looking for some compassion and support. Kerry's only reaction is to ask if she's told anyone about their relationship, which she wants to keep secret, fearing that their homophobic supervisor will find some contrived reason to fire her. Kerry promptly spends the rest of the episode doing everything she can think of to make sure that the relationship remains a secret, to the point where she refuses to even ''look'' at the woman, much less say a single word in her defense, lest it make anyone suspect that they're involved. When the hurt, angry, and fed-up woman dumps her, Kerry ''still'' doesn't get it, accusing her of not considering Kerry's feelings in the whole mess.
* JerkassHasAPoint:
** One of her defining traits, especially when it comes to the ER budget. She might be an ass, but it's not her fault that the hospital doesn't have the money for more vital equipment.
--->"Mark, just because something's my idea doesn't make it a ''bad'' idea."
** She once overheard a medical student trying to find the drug "Obecalp" in the big book of drugs, as a doctor prescribed it to a patient. Quickly realizing, and informing the student, that it is "Placebo" backwards, she stops the student and goes to rip the doctor a new one for this foolish behavior. Not only is he misleading the patients whose son might need real help by this, if something ''does'' happen then the doctor has opened the hospital up to major litigation.
** She's also rightfully pissed off at her girlfriend Sandy when the woman outs her in front of ER staff by planting a ForcefulKiss on her. It's not Sandy's place to decide that Kerry should be out of the closet.
* KarmaHoudiniWarranty: Her double-dealing almost always puts her at the head of the pack, until toward the end of the show she finally made the mistake that cost her her career: her newest hire Victor Clemente, though a genuinely talented doctor, was also an extremely violent paranoid schizophrenic. She's out the door midway through Season 13. [[AlasPoorVillain It's still really sad]].
* LipstickLesbian: Of the "chapstick" variety. Short-haired and abrasive, but very pretty and when she's not at work, she's rather feminine.
* LovableTraitor: She will knife anyone in the back in the name of "hospital policy" and yet we still feel sorry for her when she doesn't get what she wants.
* MysteriousPast: It took ''ten'' years to find out why she needed a crutch to walk.
* NeverMyFault: She never once acknowledges that the reason everyone disliked her was because of the way she treated people, as well as dumping the blame for a patient's death onto the two doctors who treated him, conveniently ignoring the fact that as their supervisor, she should have been there to correct their errors instead of off-site handling personal business. When one of the doctors confronts her about this, she has the nerve to take it even further, implying that she was completely justified in what she did because of the other woman's mistakes.
* NiceGuysFinishLast: She proves this repeatedly as she angles her way into positions of authority while engaging in ChronicBackstabbingDisorder, BaitAndSwitchTyrant and NeverMyFault. She started out as Chief Resident in the ER, eventually started running the ER, even though Mark had more seniority and had more respect (and was a better doctor), eventually becoming Chief of Staff of the entire hospital.
* NotGoodWithPeople: While no one would deny she's an excellent physician, no one likes her much either. It's very telling that despite probably being the most qualified applicant, she's consistently passed over for the ER Chief position and ultimately has to resort to underhanded methods (backstabbing Mark by reneging on her promise to fight Romano's appointment as Chief of Staff) to get the job.
* ThePeterPrinciple: With each promotion, she proved herself unworthy of them, at least to the audience. Thanks to her NeverMyFault tendencies, and the fact that she was such a RulesLawyer when it came to subordinates that she was more than willing to find and highlight their mistakes over her own, she was rarely ever called out for this, and just kept moving up. Finally it came back to bite her, and she lost her job.
* PetTheDog: Could be genuinely compassionate with her patients when necessary.
* PutOnABus: Midway through Season 13.
* [[SecondEpisodeIntroduction Second Season Introduction]]: She's one of the show's longest running characters--11 years--but didn't join the show until its second year, and didn't even become a main character until the third.
* SuddenlySexuality: Prior to her relationship with Kim Legaspi, Kerry had several relationships with men, even revealing to Kim that she had been married once before.
* SugarAndIcePersonality
* SweepsWeekLesbianKiss: Twice. Unlike most examples, however, this wasn't just a ratings grab, but rather part of a larger arc involving Kerry coming to terms with her sexuality. Both of the women she kissed appeared again.
* TinyTyrannicalGirl
* TooHappyToLive: She and her wife Sandy are blissfully happy, having just had a baby boy named Henry and comfortably settled into their domestic routine...when Sandy is fatally injured in a fire.
* UptightLovesWild: Her and her girlfriends upon her coming out of the closest. Aside from their carefree, fun-loving personalities clashing with her prim and proper one, they were also comfortable and open with their sexuality while Kerry acted downright terrified to even be seen with them in public, at one point literally hiding to avoid running into two of her coworkers while out on a date.

[[folder:Anna Del Amico]]
!!'''Anna Del Amico'''
->'''Played By''': Maria Bello

* AscendedExtra: Appeared in the last three episodes of Season 3 before becoming a main cast member in Season 4.
* InferioritySuperiorityComplex: Had an incredibly sanctimonious attitude towards rich people, probably stemming from insecurities about growing up poor.
* MsFanservice
* PutOnABus: After Season 4. Unlike most examples here, she doesn't return.
* RedHerring: As a pediatrician, there was speculation that she'd been brought on to be a new girlfriend for Doug--indeed, she initially seems very attracted to him. Only for Doug to reconcile with Carol as had been hinted at for weeks and Anna to be a love interest for Carter instead.
* StrawFeminist:
** She tended to react to everything Doug said as though it was an attack or an advance, even though he was either just being friendly (asking her if she wanted something to eat after they'd both been on the streets looking for a runaway) or just offering his years of experience (offering to do a testicular exam on a patient because he might be uncomfortable with a woman doctor). Kerry seems to agree with her claim that Doug is threatened by women, but of course Kerry had been brow-beating and annoying him about publishing his thesis for his fellowship and just couldn't see that Doug (or anyone else for that matter) simply didn't want her help.
** Nor it did occur to Kerry that Doug's problem was simply with ''her'', given her abrasive personality and their constant clashes and nothing to do with her gender.
* TheyCallMeMisterTibbs: Basically rips Doug's head off when he calls her by her first name rather than "Dr. Del Amico" in front of a patient. Keeps doing it even though he apologizes and assures her that he meant nothing improper, "I call Mark (a male doctor) by his first name all the time."
* UnresolvedSexualTension: With Carter.
* WeHardlyKnewYe: Lasted only one season.

[[folder:Elizabeth Corday]]
!!'''Elizabeth "Lizzie" Corday'''
->'''Played By''': Creator/AlexKingston

* TheBusCameBack
* ClingyJealousGirl: When Susan returns. Granted, she has a point, as Mark loved Susan passionately enough to race to Union Station to tell her so and then had a small breakdown when she left.
* FieryRedhead
* GoodBadGirl: Very openly sexual in her conversation and behavior, especially when first introduced.
* HerHeartWillGoOn
* HeroicBSOD:
** Elizabeth treated a patient from Zambia who suffered from back pain, caused by a herniated disc. The patient didn't want open back surgery and Elizabeth had planned to go on a trip with Mark that evening so she suggested a less invasive procedure instead. The patient ended up paralyzed after leaking cerebral-spinal fluid and he sues Elizabeth for malpractice. The case eventually gets settled because the patient decided to sue the manufacturer of the surgical equipment instead, but Elizabeth continued to blame herself for the incident (even though the reason he was paralyzed in the first place is because one of the waldoes wouldn't grip the bone fragment in his spine) and promptly spent weeks avoiding the OR at all costs
** Elizabeth has a breakdown during her wedding, making known her fear that Mark's tumour will return and her fear of him being hurt or ending up dead. Both of these fears end up being realised.
* {{Hypocrite}}:
** Is pissy about Mark and Susan working together, even though they were never actually romantically involved and even though every day she works side-by-side with her ex-lover Benton.
** She also chastises a fellow surgeon who asks her to speed up an operation because he wants to go to a ball game, when she herself rushed through an operation because she wanted to leave for a romantic weekend with Mark, permanently crippling the patient (to be fair, it could be that it's because of this error that she's lecturing the other doctor).
* ItRunsInTheFamily: Her mother and father are both scientists. Her father is a surgeon, her mother is a physicist.
* MamaBear: When Rachel asks if there's anything she can do to make up for nearly killing Ella with an ecstasy tablet, Elizabeth, ill with flu, fixes Rachel with her sunken, bloodshot eyes and says, "You can leave."
* OfficialCouple: With Mark.
* OneTrueLove: Mark. Elizabeth's relationships before and after Mark all fail for one reason or another, in the latter case probably because of [[TheLostLenore her love for Mark]]. When Benton asks her if she's seeing anybody in the series finale (seven years after Mark's death), she says that she's become far more focused on raising her daughter and working on her career.
* PutOnABus: Partway through Season 11.
* ReplacementLoveInterest: For Susan, with Mark.
* SomeoneToRememberHimBy: Mark did manage to give her a daughter, and spend the first year of her life with her (long enough to hear her say her first words and see her learn to walk) , before he finally succumbed to cancer.
* TheyCallMeMisterTibbs: Inverted. She's confused when someone refers to Benton, a surgeon, as "Dr. Benton" and needs to adjust to being called "Dr. Corday", rather than "Miss", as she was back in England.

[[folder:Lucy Knight]]
!!'''Lucy Knight'''
->'''Played By''': Kellie Martin

* AudienceSurrogate: Brought in because Carter, the previous audience surrogate, was now a fairly experienced and accomplished doctor.
* BelligerentSexualTension: She and Carter fight. A lot. They end up making out in "The Storm, Part 1", but it never goes any further--Creator/NoahWyle was adamantly opposed to the relationship, feeling that it was improper, as Lucy was still a medical student and therefore Carter's subordinate, and out-of-character for Carter.
* CharacterDevelopment: Despite her brief time on the show, she went from being a bumbling, clueless medical student to a very competent one who would no doubt have been an excellent physician.
* CousinOliver: It was explicitly stated that she was brought on to bring some new blood to the now five-year old series.
* TheCutie
* DistaffCounterpart: As an inexperienced third-year medical student, she was essentially a female version of Season 1-Carter.
* KillTheCutie
* MoralityPet: For Romano.
* NaiveNewcomer
* WeHardlyKnewYe: Lasts only a season and a half. Despite the professional development that Lucy undergoes, the audience never gets to know much about her personally.

[[folder:Robert Romano]]
!!'''Robert "Rocket" Romano'''
->'''Played By''': Paul [=McCrane=]

* AlliterativeName: Combined with his nickname "Rocket", he has a triple alliterative name.
* AnArmAndALeg: He loses an arm to a helicopter rotor.
* AscendedExtra: Made frequent appearances during Seasons 4 and 5 before being bumped up to series regular status in Season 6.
* AtLeastIAdmitIt: For all his numerous flaws, as Cleo called him, "a racist, sexist, elitist jackass," there was no denying that he never once hid the fact that he was a colossal egomaniac who couldn't be trusted and whose primary concern was himself.
* BaldOfEvil
* BeardOfSorrow: He sports this after he loses his arm in a helicopter accident.
* BunnyEarsLawyer: He just wouldn't be able to keep his job if he wasn't very good at it. He pulls some outrageous stunts, says and does things that would be considered completely inappropriate, almost no one likes him and he tries his very best to alienate the one person (Elizabeth) that does.
* DeadpanSnarker: On steroids. His insults were frequently works of art.
* DrJerk
* DroppedABridgeOnHim: For a character with such an extensive history on the show[[note]]By Season 10, the only main characters who had been around longer than him were Carter, Kerry, Elizabeth, Jing-Mei and Susan. Even then, the latter two had been PutOnABus respectively during Seasons 1 and 3 and only returned after Romano had been made a main cast member[[/note]], he suffers a pretty ignoble (though memorable) death when a helicopter falls squarely on top of him, a full year ''after'' a separate helicopter had torn one of his arms off.
* EvenBadMenLoveTheirMamas: A episode that took place near Mother's Day had him enthusiastically describing the elaborate plans that he had for his mother, much to the shock of the other staff members.
-->'''Romano''': Bet you didn't even think I ''had'' a mother, did you?\\
'''Haleh''': Can't imagine what she's like.
* EvenEvilHasStandards: Is genuinely angry and disgusted at the dishonest stunts Kerry pulls.
* {{Flanderization}}: When he first appeared his bad traits were relatively low-key. The more often he appeared, the worse he got.
* HeroicBSOD: After his arm is reattached and he realizes he might never regain full mobility, then after he realizes it can't be saved and needs to be amputated for good, effectively ending his surgical career.
* HiddenDepths:
** Adores his dogs, studies martial arts (as evidenced by him showing up at work in such a uniform), is a member of the Polar Bear Club (he mentions it to Susan in one Season 8 episode and a deleted scene [[FanDisservice shows him in a Speedo]] having taken one of the elderly members to the ER) and knows sign language.
** He is also the only one to tell Elizabeth to go back to Mark. This is especially a touching scene because Elizabeth was probably the only woman he had genuine above-the-belt feelings for, and yet he told her to go back to her husband instead of attempting to use her moment of weakness to his advantage.
** His devastation at the realization that he might never be able to perform surgery again--a fear that ultimately comes true--reveals that for all his {{Jerkass}} ways, he genuinely loves his job and being able to help people.
* HopelessSuitor: For Elizabeth.
* InsufferableGenius
* JerkassHasAPoint: Frequently. He may be an absolute a-hole, but when it comes to medical ethics and procedure, when he turns on the blasters, he's usually right. He would lash out against people for their incompetence and, in one case, illegal behavior. During a major rush of patients, he found Morris smoking pot. He ripped the younger doctor out of the bathroom stall and put him at the entrance desk, telling Morris to not move until he came back. The punishment never happened primarily because in a short time Romano would be killed by the chopper, no one realizing this, and [[KarmaHoudini Morris]] never telling anyone why Romano told him to stay still.
* KindheartedCatLover: Rushes his own dog into surgery because he refused to trust her welfare to "some poodle surgeon."
* LonelyFuneral: Romano was so disliked that Elizabeth was the only one to show up at his funeral.
* PetTheDog: However rare they were, his NiceGuy moments were genuine. Even some of his supposedly {{Jerkass}} moments revealed that he was actually doing someone a favor--assisting a heavily pregnant Elizabeth with surgery, giving Benton time off to spend with his son, concern for the ailing Mark. Plus, the literal examples with his beloved animals, as well as his genuine fondness for Lucy.
* PoliticallyIncorrectVillain: The first thing he does when introduced is ask Benton why he doesn't have NWordPrivileges when Creator/ChrisRock does.
* ProperlyParanoid: In Season 10, he rides the elevator up to the hospital helipad with Neela to drop off a patient's watch that had been left behind. However, seeing the helicopter ready to take off triggers flashbacks to the loss of his arm from the year before, and he quickly gives the watch to Neela before heading back down himself. He turns out to have been completely justified in his fears, as the helicopter starts to fly out of control shortly after taking off due to the strong winds. If he had stayed on the roof, he may well have been impaled by some debris just like the doctor left behind with Neela was. Unfortunately, Romano dies anyway when he takes a walk outside in the hospital parking lot to clear his head, as the helicopter ends up crashing right on top of him.
* ShoutOut: When he's in the OR he wears a bandana with rockets on it. Whether the bandana or the nickname came first is never specified.
* TokenEvilTeammate
* {{Ubermensch}}
* UglyGuyHotWife: Romano has been seen with some very attractive girlfriends.

[[folder:Luka Kovač]]
!!'''Luka Kovač'''
->'''Played By''': Creator/GoranVisnjic

* BerserkButton: Wife-beaters, child-abusers, just AssholeVictim patients in general.
* TheCasanova: Like Mark, Luka had never been with anyone other than his first wife Danijela before he started seeing other women. Unlike Mark, Luka actually knows how to charm them.
* ChronicHeroSyndrome: Likely because he was unable to save his own family during the war, he develops this, often to his detriment--he takes a waitress from his favorite bar under his wing, blithely ignoring all signs that she's a thief and a liar.
* CommutingOnABus: Throughout Season 14. Notably, Goran Višnjić does not appear on the DVD cover for the season, but is first-billed as a member of the main cast in all of the episodes he appears in (7 out of 19). InUniverse, Luka spends most of it off-screen in Croatia to be with his dying father, occasionally appearing to see Abby and their son Joe. He eventually returns to Chicago full-time, only to spend time away from Abby when she reveals that she cheated on him. He forgives her in the season finale, and turns up one final time in the third episode of Season 15 for them to depart County Hospital together.
* DarkAndTroubledPast
* EarnYourHappyEnding: After everything Luka went through both before and during the series, he eventually got a happy ending with Abby and their son.
* HappilyMarried: To Abby. He was also this to Danijela, which is why he suffered a HeroicBSOD upon her death and the deaths of their two children.
* HeroicBSOD: Plenty of these for him too, all of which seem to happen just as things are getting better for him--he starts to recover from the loss of Danijela and their two children Jasna and Marko by falling in love with Carol; despite briefly dating, Carol leaves him to reunite with Doug. He starts to recover from ''this'' by dating Abby, then he kills a mugger attacking them. One even happens out of nowhere then gets even worse after he almost kills a co-worker in a car accident.
* HugeGuyTinyGirl: He's 6'4", while his main love interest Abby is 5'3".
* IWantMyBelovedToBeHappy: The reason he breaks up with Abby the first time. He bends over backwards to try and make her happy, but she's always miserable and content with being so. It gets to the point where they have a fight, he says a lot of things he didn't mean, and they break up.
* OfficialCouple: With Abby.
* SayYourPrayers: He did this in one episode while in the Congo, but winds up living through it. Subverted since the praying saves him--the rebels holding him think he's a priest and [[EvenEvilHasStandards shooting priests is the one thing they won't do]].
* ShellShockedVeteran: He lost his first wife and two children in the Yugoslav wars. Quite a lot of his behaviour can be attributed to HeroicBSOD.
* SuspiciouslySimilarSubstitute: A brooding hunk with allusions to a mysterious, tragic past and a not-so-secret longing for Carol? He was referred to as "Euro Ross" on many other fan boards (his resemblance to Doug didn't help much to dispel this). A period of promiscuity for him pretty much cinched it. Not to mention the fact that he falls in love with and eventually marries Carol's effective replacement Abby.
* TallDarkAndHandsome
* TroubledButCute
* UnexpectedVirgin: During a scene where several other characters are discussing when they lost their virginity, he admits that his first time was on his wedding night.
* UnresolvedSexualTension: With Carol. Especially bad as from his side of things, developing feelings for her was an indication that he was recovering from the deaths of his wife and children.
* YoungerThanTheyLook: Actor Goran Višnjić was 27 during his first year on the show. He easily could have passed for 40 and was immediately shown to be an authority figure (already an Attending) in the ER. Which also makes this a case of either PlayingGertrude or ImprobableAge, as there's no way he'd be an Attending so young.

[[folder:Cleo Finch]]
!!'''Cleo Finch'''
->'''Played By''': Michael Michele

* BlackAndNerdy
* ClingyJealousGirl: Gets pissy about going to Mark and Elizabeth's wedding, even Benton and Elizabeth broke up ''three years before''.
* DarkSkinnedBlond
* DistaffCounterpart: To Benton. Her aloof, reserved personality is very similar to his.
* FlatCharacter: As she never served any purpose but to be Benton's African-American girlfriend, she got zero individual storylines and we learned very little about her during her two years on the show.
* HalfBreedDiscrimination: Against ''herself''. It's implied that the reason for her hypersensitivity about race issues is compensation for being of mixed race and having grown up in the suburbs.
* HappilyMarried: To Benton.
* {{Hypocrite}}: Her few scenes with Elizabeth indicate that she disapproves of the fact that Elizabeth and Benton once had a relationship, even though Cleo herself is the product of such a union.
* MalcolmXerox: For a while, tended to see racism as the reason behind every slight or reprimand.
* OfficialCouple: With Benton.
* PluckyGirl
* PutOnABus: After Season 8. Unlike most examples here, she doesn't return.
* SuspiciouslySimilarSubstitute: Inverted. She's Doug's opposite in practically every way, right down to their race and gender, except for being a skilled and dedicated pediatrician just like he was.

[[folder:Dave Malucci]]
!!'''Dave Malucci'''
->'''Played By''': Erik Palladino

* ZeroPercentApprovalRating: '''Everybody''' hates this guy, from the moment he shows up to the moment he leaves.
-->'''Elizabeth''': [[BrutalHonesty In short, none of us thinks you're much of a doctor]].
* AbusiveParents: Implied, given his reaction to them.
* AscendedExtra: Spent his first few episodes credited as a guest star before being added to the opening credits.
* BunnyEarsLawyer: Deconstructed. He's initially presented as a SuspiciouslySimilarSubstitute to Doug: brash, impulsive, problems with authority, womanizing, etc. Eventually, however, RealityEnsues--he makes numerous mistakes, is warned by Elizabeth that "[[BrutalHonesty none of us thinks you're much of a doctor]]" (unlike Doug, Malucci is considerably dumber than the other doctors and also much lazier), and is finally fired both when his misdiagnosis kills a patient and when he's caught having sex with a paramedic while on duty.
* CasanovaWannabe: Hits on practically every woman in sight, all of whom reject him. Even the woman he's caught having sex in an ambulance with blew him off initially.
* CunningLinguist: Speaks Spanish.
* DumbassHasAPoint: On several occasions.
* DumbJock: A doctor variant. Attended medical school in Grenada because he did poorly in college and on his [=MCATs=].
* HiddenDepths:
** Claims to have a child, although this may have been an appeal to Kerry's emotions.
** He actually proved to be a pretty decent doctor on the rare occasions that he got his act together and stopped goofing off.
* IdiotBall: Despite knowing full well that Kerry is out for blood due to his part in killing a patient, Malucci sneaks off to have sex with a gorgeous paramedic. Kerry catches him and subsequently fires him.
* JerkWithAHeartOfJerk: Unlike his predecessor Doug, there's very little beneath Malucci's philandering DumbJock exterior. He's ultimately fired for having sex in an ambulance, with his one moment of depth (see above) being in his very last episode.
* KickTheDog: He claims to have a child to support. Kerry fires him anyway. Later, Malucci's last mention on the series was Carter telling Gallant that he was reckless and killed a patient.
* MonsterClown: He has some unresolved fear of clowns.
* NosyNeighbor: Shortly after joining the staff, he interrogates everyone about why Kerry limps. He finally admits it's none of his business after she confronts him about it, but still fails to learn his lesson--one year later, he does exactly the same thing regarding the paternity of Jing-Mei's baby.
* PetTheDog: Despite his incompetence and the rest of the staff's utter contempt for him, Mark seems to rather like Malucci and stands up for him when Kerry fires him. Perhaps it's because he reminds him of Doug.
* PutOnABus: Partway through Season 8. Unlike most examples here, he doesn't return.
* SuspiciouslySimilarSubstitute: Like Luka, Malucci was given many of Doug's characteristics--brashness, impulsiveness, problems with authority, an antagonistic relationship with Kerry (bizarrely, in ''both'' cases, fanfic writers opted to interpret this as BelligerentSexualTension and pair them), and a once-mentioned but never explained kid, along with a BerserkButton reaction to abusive parents that likely stemmed from his own experiences. To the point where ''his'' fan board nickname was "Doug Ross, Jr."
* WeHardlyKnewYe: Lasted only a little over two seasons and got zero CharacterDevelopment.

[[folder:Jing-Mei Chen]]
!!'''Jing-Mei Debra "Deb" Chen'''
->'''Played By''': [[Creator/MingNaWen Ming-Na Wen]]

* AscendedExtra: She was a recurring character in Season 1. After being absent for five years, she became a regular.
* AsianAndNerdy
* TheBusCameBack: Returns as a regular halfway through Season 6.
* ChekhovsGunman
* ClingyJealousGirl: Is understandably pissy about Pratt flirting with Neela right in front of her, but she unfairly takes it out on ''Neela'', who was completely unaware of their relationship.
* GoodGirlsAvoidAbortion: When she reveals her pregnancy to Kerry, she implies that she deliberately hemmed and hawed about what to do until it was too late to terminate.
* FamilyVersusCareer:
** Having quit her job in anger after realizing that Kerry screwed her over, she tearfully tells Carter, "Whatever sacrifice you make for this place, make sure it's worth it," indicating that the reason she gave up her son for adoption was to focus on her career and that she now regrets it.
** She also quits for good to euthanize her dying father and bury him in his native China.
* HeroicBSOD: Has at least two. One after the infamous guide wire incident. Another for simultaneously giving up her son for adoption (she knew she could've easily taken care of him but was too concerned with what her overly traditional family might think) and for losing a patient and being back-stabbed by Kerry.
* ItRunsInTheFamily: Her parents are doctors as well.
* TheNotLoveInterest: To Carter. Despite a slight attraction and flirtation, their relationship never goes beyond a very good friendship.
* TheOjou
* OnlyKnownByTheirNickname: When she first appeared she went by her western name, Debra "Deb" Chen. When she returned as Jing-Mei, Carter insisted on always calling her "Deb."
* PutOnABus: After Season 1. Then midway through Season 11, leaving Chicago to bury her father in his native China. Unlike most examples here, she doesn't return.
* ScrewThisImOuttaHere:
** She actually resigns altogether following her demotion and Kerry's backstabbing.
** There's a sadder version several years later when she can no longer keep up with the demands of her job and caring for her ill father, especially when Susan tells her that she can no longer make allowances for her.

[[folder:Abby Lockhart]]
!!'''Abigail "Abby" Marjorie Wyczenski Lockhart'''
->'''Played By''': Maura Tierney

* AbusiveParents: Subverted. While her mother may not have been willfully abusive or neglectful, it's still clear that Abby's childhood was hell thanks to her mother's UsefulNotes/BipolarDisorder, a mental illness that she consciously chose not to seek help for.
-->'''Maggie''': I never asked to be sick!\\
'''Abby''': You never tried to get better!
* TheAlcoholic
* AscendedExtra: In her first appearance, she was an OB nurse at Carol's birth. Not long after, she appeared in the ER as a medical student, and was later transferred to be an ER nurse after being forced to drop out of medical school.
* ClingyJealousGirl: Is a complete bitch to and about Luka's new girlfriend Nicole, even though she and Luka have broken up and is similarly nasty to and about Susan whenever she sees her with Carter, even though she and Carter haven't even been together yet.
* DeadpanSnarker: Has her moments. Most notably as a nurse and occasionally after she has Joe.
* EarnYourHappyEnding: After everything, Abby finally gets her happy ending with Luka.
* GoodGirlsAvoidAbortion: Averted. She had one during her first marriage out of fear of putting a child through the same hell she went through, or the child itself being mentally ill. But played straight when she gets pregnant by Luka, despite still having the same fears.
* HappilyMarried: To Luka.
* HeterosexualLifePartners: With Neela.
* JadeColoredGlasses
* TheMasochismTango: She outright calls her and her mother's interactions "The dance we do"--she shows up in the beginning stages of mania, swearing that things are going to be different, but eventually going completely off the wall and causing chaos, then disappearing for months before turning up again, this time in a depressed phase, possibly to the point of being suicidal. Despite how miserable the whole thing makes Abby, it's obvious that she can't bring herself to get out of it.
* OfficialCouple: With Luka.
* OffTheWagon
* ParentalSubstitute: Was this to her own mother and brother whenever her mother was in a manic or depressive state.
* PutOnABus: Near the very beginning of the final season ("The Book of Abby"), she leaves the ER to be with Luka and Joe in Boston. She makes one final return in "Shifting Equilibrium" via [[TheCameo phone call]] in order to reassure Neela on the latter's last day working at County Hospital.
* ReallyGetsAround: It's implied that she slipped into this kind of behavior whenever she was drinking.
* SingleWomanSeeksGoodMan
* SuspiciouslySimilarSubstitute: She replaced Lucy as the "bumbling and clueless" medical student after the latter's death. Then, though their personalities and backgrounds were vastly different, she replaced Carol as the token nurse character once the latter left. Interestingly, when Abby first appeared on the show, she was precisely at the point Carol would have been in her medical studies had she decided to go to medical school.
* YourCheatingHeart: Her first husband cheated on her (in his defense, this was after she froze him out following her abortion), and she sleeps with another man while Luka is away in one of her alcohol-induced blackouts.

[[folder:Michael Gallant]]
!!'''Michael Gallant'''
->'''Played By''': Sharif Atkins

* AdvertisedExtra: He was promoted to the main cast shortly after his first appearance. If anything, the series made ''less'' use out of him after promoting him than before.
* BlackAndNerdy
* CommutingOnABus: In Seasons 11 and 12 until he died.
* FirstLove: To Neela.
* FourthDateMarriage: He and Neela express a mutual interest in each other in Season 10, but he gets shipped off to Iraq before he ever officially asks her out. From then on, [[LongDistanceRelationship their relationship takes place via letters and e-mails]]. It's not known if they ever even ''had'' a proper date before he returns on leave and proposes to her, with them marrying that same day. This is acknowledged when, a month after they've married and they argue over his wanting to return to Iraq and her not wanting him to, Neela admits to her dismay, "I love you, but I still don't ''know'' you."
* GoodLookingPrivates: Whenever we'd see him in uniform.
* KilledMidSentence
* MeaningfulName: Gallant, obviously. To the point where his final episode is named after him--"The Gallant Hero and the Tragic Victor".
* PutOnABus: After Season 10.
* RedOniBlueOni: The Blue to Pratt's Red. Pratt is more impulsive, while Gallant is by the book.
* TooHappyToLive: Mentions his wife Neela and how much he's looking forward to going home and seeing her not five seconds before the truck he's riding in is blown up, killing him.
* TookALevelInBadass
* WideEyedIdealist

[[folder:Greg Pratt]]
!!'''Gregory "Greg" Pratt'''
->'''Played By''': Mekhi Phifer

* AscendedExtra: He appeared in four episodes towards the end of Season 8, before being promoted to the main cast in Season 9.
* BackForTheDead
* BadassBeard
* BlackAndNerdy
* BlackBestFriend: Inverted. While he is technically this to Morris, he is the more prominent character.
* CharacterDevelopment: Started out very impulsive and egotistical. By his tenure's end, he'd become an excellent teacher and was about to be named ER Chief.
* MeaningfulName: He ''is'' a bit of a prat, after all.
* RedOniBlueOni: The Red to Gallant's Blue. Later on the Blue to Morris' Red.
* SuddenSequelDeathSyndrome: Died at the ''final season'' premiere.
* TooHappyToLive: Was preparing to propose to his girlfriend and had just been named the new ER chief when he was killed.

[[folder:Neela Rasgotra]]
!!'''Neela Rasgotra'''
->'''Played By''': Parminder Nagra

* AbsenceMakesTheHeartGoYonder: Subverted and Defied. She and Gallant contact each other as much as they can throughout [[LongDistanceRelationship their relationship]], and both are able to resist cheating on each other, although they nearly came close to doing so--he with one of his coworkers in Iraq, she with Ray's bandmate Bret. After she realizes she's in love with Ray, she moves out of their apartment to remain faithful to Gallant.
* AsianAndNerdy: Is a Brit of Indian descent and a medical student-turned physician-turned surgeon.
* BewareTheQuietOnes
* CharacterDevelopment: Goes from a shy neophyte, to confident physician, to even more confident surgeon.
* {{Claustrophobia}}
* CommutingOnABus: Officially departs the ER in the antepenultimate episode, but manages to make brief appearances in the final two episodes.
* DeadpanSnarker: Ray tended to bring this out of her, before and during the time they were roommates.
* EarnYourHappyEnding: After everything she went through, she finally gets her happy ending with Ray.
* HerHeartWillGoOn: While affected by Gallant's death at the end of Season 12, she does continue to engage in relationships afterwards, with Gates, Brenner, and Ray.
* HeroicBSOD: She has one so bad after being notified of Gallant's death that she turns around and picks up two charts to go back to work, as if nothing happened.
* HeterosexualLifePartners: With Abby.
* LethalChef: According to Ray, her cookies are "[[BrutalHonesty the worst cookies ever made in the history of baking]]." Frank, Chuny and Morris agree with him, although they're more polite about their opinions.
* NaiveNewcomer: Takes on the role of the "hapless medical student" for the show in Season 10. She gradually grows out of it over the next year.
* OfficialCouple: With Ray.
* OneTrueLove: Ray. Neela's other relationships all fail for different reasons--with Gallant, it was because they barely knew each other, as well as his returning to Iraq despite her not wanting him to, which led to his death; with Gates, it was his constant lying and issues with Meg and Sarah; and with Brenner, it was his inability to open up to her about anything. In stark contrast, her relationship with Ray is open and honest; she enjoys spending time with him and is genuinely happy around him; and even when she dated other guys, she sought ''him'' out for advice instead of them, proving she holds a deep trust in him.
* ProgressivelyPrettier: Goes from merely "cute" when she first joins the staff to positively drop-dead gorgeous by the time she leaves.
* SheCleansUpNicely
* SuspiciouslySimilarSubstitute: She shares a few characteristics with Carol. Most notably, their love lives are similar--both Neela and Carol married[[note]]Or, in Carol's case, ''almost'' married[[/note]] their first on-screen boyfriends, Gallant and Tag; both of their second boyfriends, Gates and Shep, are paramedics; both only briefly dated their third boyfriends, Brenner and Luka; and both left County Hospital to reunite with their fourth and final boyfriends, Ray and Doug.

[[folder:Sam Taggart]]
!!'''Samantha "Sam" Taggart'''
->'''Played By''': Creator/LindaCardellini

* AllGirlsWantBadBoys: Played Straight with her ex-husband Steve and final boyfriend Gates. Inverted with Luka.
* ClingyJealousGirl: Is furious when she sees that Luka has hooked up with the woman he had a fling with while in Africa, even though she herself told him she wanted to take a break. She later gets pissy when Neela develops a short-lived crush on him. A few years later, while dating Gates, she does the same thing--breaks up with him outright, but gets angry when he begins dating someone else.
* EstablishingCharacterMoment: Proceeds to take a needle of a sedative from Morris, jumps in and proceeds to inject the sedative into a mentally disturbed guy who was being incredibly aggressive.
* GoodGirlsAvoidAbortion: By the time she saved the money for an abortion, she couldn't work up the nerve to go through with it.
* MamaBear: Don't mess with Alex or else she will come after you.
* SuspiciouslySimilarSubstitute: Replaced Abby as the token nurse once Abby decided to return to medical school, though their personalities are very different.
* TeenPregnancy: She had her son Alex at age 15. Unlike most teen pregnancies though, Sam and her son are fairly level-headed.
* WifeBasherBasher: Punches out an abusive boyfriend when he not only calls the girl a slut, he grabs Sam's arm, arguably making her actions self-defense.

[[folder:Ray Barnett]]
!!'''Ray Barnett'''
->'''Played By''': Shane West

* AbusiveParents: A BerserkButton for him. In a deleted scene from Season 12, it's implied, but not explicitly stated, that he had a stepfather who suffered from substance abuse. In "Split Decisions", he threatens Zoe's father after he learns that the man beat her. In "A House Divided", he becomes angry with a stepfather who mistreated his stepson, and he tells Kerry that the man reminded him of someone he used to know.
* AnArmAndALeg: He has both of his legs amputated after getting run over by a truck. He later has them replaced with prosthetics.
* BettyAndVeronica:
** In Season 12, he's the Veronica to Gallant's Betty for Neela's Archie: Gallant's a military doctor and devoted to Neela, while Ray's a part-time rock musician and a womanizer. Despite Neela and [[LadykillerInLove Ray]] falling in love, she chooses to remain faithful to her boyfriend-turned-husband Gallant.
** In Season 13, he's the Betty to Gates' Veronica for Neela's Archie: [[CharacterDevelopment Ray's a serious third-year resident]] who's honest with everyone, while Gates is an arrogant ER intern who constantly lies to save his own neck. Despite Neela initially choosing Gates because she was OnTheRebound from losing Gallant, she quickly becomes miserable in the relationship. During Luka and Abby's wedding, Neela breaks up with Gates and chooses Ray...right before the latter gets run over by a truck.
** Also in Season 13, he's the Archie for Neela's Betty and Katey's Veronica: Neela's a serious surgical intern who tries to separate her personal life from her professional life, while Katey's an incompetent medical student who doesn't mind that everyone--''especially'' Neela--is aware of her relationship with Ray. Despite dating Katey, Ray doesn't actually care about her because he already chose Neela in Season 12, and [[OperationJealousy he only dates Katey because he's jealous of Neela's relationship with Gates]].
** In the final season, he's the Betty to Brenner's Veronica for Neela's Archie: Ray has come to terms with his accident and enjoys working in the physical medicine and rehabilitation field to help fellow amputees and handicapped patients, while Brenner can't come to terms with his abusive childhood and prefers sleeping around over being an efficient Attending. Despite briefly dating Brenner, Neela already chose Ray at the end of Season 13, and she ultimately leaves [[DidNotGetTheGirl Brenner]] to be with Ray.
* ButtMonkey: Goes through a bit of trouble, culminating in him losing both of his legs near the end of his tenure as a main cast member. Fortunately, things get better for him when he returns in the final season.
* CommutingOnABus: After being absent in Season 14, he reappears throughout the final season, far more well-adjusted than he had been in the past, and reignites his relationship with Neela. In the antepenultimate episode, she leaves Chicago to be with him in Baton Rouge, and the penultimate episode reveals that they're living together again.
* DisappearedDad: Both his biological father and stepfather are mentioned but never shown on-screen. He speaks fondly of his biological father in "Quintessence of Dust", telling one of his patients that his father got him into music and loved the blues. He doesn't feel the same way about his stepfather, though.
* DoggedNiceGuy: Towards Neela. He tries to [[DefiedTrope Defy]] this by telling her that he's sick of waiting for her to choose him over Gates. However, it's still Played Straight--after Neela loses interest in Gates due to his constant lying and issues with Meg and Sarah, and after Katey breaks up with him because she knows he only has eyes for Neela, Ray admits that he believes his commitment and patience in waiting for Neela to reciprocate his feelings will win her heart.
* EarnYourHappyEnding: After everything he went through, he finally gets his happy ending with Neela.
* FriendToAllChildren
* HopelessSuitor: For Neela in Seasons 12 and 13.
* InspirationallyDisadvantaged: Following the accident that results in the amputation of both of his legs. When he returns to Chicago for a visit in the final season, he's been fitted with prosthetics and is living as normal a life as possible and has used his injuries to focus his medical practice on those in similar situations.
* LadykillerInLove: He hooks up with groupies and "hot" women and claims to like them, but he doesn't genuinely care about them. In stark contrast, he outright confesses and shows that he's truly fallen in love with Neela.
* MrFanservice: Getting introduced as part-time doctor and part-time rock musician meant that this was inevitable.
* OfficialCouple: With Neela.
* OneHeadTaller: He's 6', while his main love interest Neela is 5'2".
* OneTrueLove: Neela. With other women, he'd state that he merely ''liked'' them, or comment on how "hot" they were, or talk about how great the sex was, all of which are superficial, and he never wanted to be serious with any of them. Conversely, Neela is the only woman he confesses his ''love'' to, he wants to take her out on dates rather than immediately jumping into bed with her, and he indicates to Pratt that he's thought about settling down with her.
* PutOnABus: After Season 13.
* ReallyGetsAround
* SecondLove: To Neela, after Gallant.
* SuspiciouslySimilarSubstitute: He shares a lot of characteristics with Doug--he's initially brash and impulsive and has issues with authoritative figures like Susan and Kerry prior to his CharacterDevelopment; he has a BerserkButton for AbusiveParents that originated from his own experiences; he has a great rapport with children; he's a handsome and charming stud in and out of the hospital; and despite his constant dalliances with groupies and "hot" women, he genuinely falls in love with Neela, who herself shares a few characteristics with Doug's true love Carol.

[[folder:Archie Morris]]
!!'''Archibald "Archie" Morris'''
->'''Played By''': Creator/ScottGrimes

* {{Adorkable}}
* AscendedExtra: He was a recurring character throughout Seasons 10 and 11 before becoming a main cast member in Season 12.
* ButtMonkey
* CharacterDevelopment: Probably the most extensive in the show's history. Started out as an annoying, bumbling, incompetent fool who no one liked. Ended as one of the best doctors in the hospital whom everyone respected.
-->'''Carter''': [[SoProudOfYou Looks like you followed my advice, Archie]].\\
'''Morris''': How's that?\\
'''Carter''': [[ArcWords You set the tone]].
* TheConfidant: Abby {{Lampshade|Hanging}}s that, by the end of the series, he's become a trustworthy person to come to when it for sharing one's issues. This is reinforced later when Catherine reveals her history with County General to him (she had brought her son there for treatment and he had died there) and Brenner confides to him about getting molested as a child.
* DrugsAreBad: He got better.
* PluckyComicRelief: In the first few years of his tenure. Downplayed later on as he becomes more competent and his comedic lines appear less and less.
* TheStoner: He got better.

[[folder:Tony Gates]]
!!'''Anthony "Tony" Gates'''
->'''Played By''': John Stamos

* AbusiveParents: He was raised by an alcoholic father. He is none too pleased when his father shows up midway through Season 13.
* AscendedExtra: He appeared in two episodes in Season 12. He became a regular in the following season.
* BerserkButton: It's not a good idea to talk about Meg's death in front of him.
* CockFight: With Ray over Neela in Season 13, culminating in a fight at Luka and Abby's wedding.
* LoveTriangle: He and Ray compete for Neela's affections throughout Season 13. She breaks up with Gates after he and Ray fight at Luka and Abby's wedding, and in the Season 13 finale, she reveals to Ray that she's chosen him over Gates. While Ray initially doesn't want to deal with Neela following his accident, they reconcile and get together in the final season, during which Gates had already moved on to having feelings for Sam, effectively ending the Love Triangle.
* MrFanservice: One of the more sexual characters in the show's last few seasons. A fair amount of his subplots deal with him romancing Neela and then Sam.
* PapaWolf: To Sarah.
* TallDarkAndHandsome: As to be expected for someone played by John Stamos. He takes over for Luka in this position after the latter starts CommutingOnABus.
* WhatTheHellHero: Is given this by Sam when he lets Alex out of the house against Sam's orders and Alex ends up in a serious car accident. It leads to the destruction of their relationship that lasts until the final episode.

[[folder:Simon Brenner]]
!!'''Simon Brenner'''
->'''Played By''': Creator/DavidLyons

* AscendedExtra: He was a recurring character towards the end of Season 14. He became a regular in the final season.
* BelligerentSexualTension: After weeks of being at each other's throats, he and Neela get into a full-fledged shouting match, which of course culminates in them going at it.
* DidNotGetTheGirl: In the final two seasons, he falls for Neela and they even briefly become a couple. However, throughout their short relationship, Neela remains in love with Ray, and she ultimately leaves both Brenner and County to be with Ray in Baton Rouge.
* EvilBrit: More like "{{Jerkass}} Aussie", but the gist is the same.
* FieryRedhead
* LadykillerInLove: His womanizing ways are established from his first scene, but he falls in love with Neela.
* {{Nepotism}}: To the point of being either a StealthPun--he's Chief of Staff's Donald Anspaugh's nephew (nepotism comes from the Latin word "''nepos''", which means..."nephew")--or a literal example of {{Nephewism}}.
* RapeAsBackstory: His BerserkButton reaction to a pedophile patient leads to him confessing to Morris in "Age of Innocence" that he was molested by one of his mother's boyfriends.
* ReallyGetsAround: His ''first'' scene is of him [[AThreesomeIsHot waking up in bed with two women]], and his womanizing reputation is well established afterwards.
* SuspiciouslySimilarSubstitute: He has a few of Doug's characteristics, namely an abusive past that influences his good (anger about abused children) and bad (sleeping around) behavior.

[[folder:Catherine Banfield]]
!!'''Catherine "Cate" Banfield'''
->'''Played By''': Creator/AngelaBassett

* BlackAndNerdy
* BlackBossLady: Not afraid to put people in their place, often with a properly stern expression.
* BrokenBird: Catherine and her husband were devastated by the death of their son. The two were estranged from one another due to the trauma of it for a fair amount of time, though they manage to reunite by the final season.
-->'''Catherine''': I'm not sure why I've done anything I've done since that day. Why'd I not leave my apartment for almost two years? Then I see the news about the tsunami, and I fly to a place 10,000 miles away. Why'd I do that? Why'd I come back? Why did my son have leukemia? I never understood any of it.\\
'''Morris''': I--I'm sorry for your loss. I...I don't really know what to say.\\
'''Catherine''': When your parents are gone, you're an orphan. When your spouse dies, you're a widow or widower. But when you lose your baby...there's no word for that.
* ChekhovsGunman: Her son was one of Mark's last few patients.
* DefrostingIceQueen: Highlighted with her and Morris' interactions. While at the start, there is some friction due to her firmness and his resentment at a stranger taking Pratt's place so soon after his death, by the time of "Heal Thyself", Catherine is able to open up to him about her son's death and Morris looks at her in a different light.
* RememberTheNewGuy: Despite her son supposedly being one of Mark's last patients, she was nowhere to be seen in Season 8.
* SecondEpisodeIntroduction: She makes her first appearance in the second episode of the final season, following Pratt's death in the first episode.
* SuspiciouslySimilarSubstitute: Bossy, abrasive, takes charge, and takes no nonsense? Sounds a lot like either Kerry Weaver or Angela Hicks.

[[folder:Jerry Markovic]]
!!'''Jerry Markovic'''
->'''Played By''': Abraham Benrubi

* CommutingOnABus: Appeared regularly up until Season 4, disappeared for a bit in the middle of Season 4 (it was later explained that he was moved to nights due to accidentally blowing up the ambulance bay), then left at the end of Season 5 for unknown reasons. Returned again during Season 8, left again during Season 13, and returned partway through the final season. His Seasons 13-15 absence was {{Lampshade|Hanging}}d as him "slinging beers in Alaska," which is a reference to Benrubi's character on ''Men in Trees''.
* GentleGiant: Was used as a bouncer of sorts on occasion, but never really got violent with anyone. In "The Human Shield", he even reminds Sam that he abhors violence.
* NewPowersAsThePlotDemands: He seemed to get hit with this a couple of times in Season 12. First, when Neela and Gallant were getting married, he suddenly morphed into a Universal Life Church minister. Later on, when they needed an ASL interpreter and Ray's own skills with the language are limited, guess who happens to be the only other member of staff with any ASL skills? None of these had been brought up prior to when they were needed, and in the case of the ASL, he had never been shown signing to anyone on staff, let alone teaching Benton or Ray. It's possible that he learned ASL after Benton's departure, but it's never made explicitly clear.
* PluckyComicRelief
* VitriolicBestBuds: Eventually becomes this with Frank, although they'd never admit it.
* WhyDidItHaveToBeSnakes: Had a fear of dead people early on in the series. Also afraid of thunderstorms, although the latter seems to be justified.

[[folder:Frank Martin]]
!!'''Frank Martin'''
->'''Played By''': Troy Evans

* AscendedExtra: Debuted all the way back in the {{Pilot}} as a cop.
* BigEater: Oh boy. This led to his heart attack.
* DeadpanSnarker: ''A lot''. Sometimes this was combined with his {{Jerkass}} behaviour, other times it was his method of communicating.
* FriendToAllChildren: Does make some snarky remarks about the staff's kids behind their back, but is shown to be more patient and concerned for their health and wellbeing compared to other patients.
* TheGenerationGap: Was implied to be the reason behind his jerkass behaviour. The further along the series went, he became less of a {{Jerkass}}.
* HiddenDepths:
** It was later revealed that he had a wife and a daughter with what looked like Downs Syndrome and was also a war veteran.
** His reaction to the deaths or injuries of various staff members (Mark, Gallant, Jerry, Pratt) reveals that he genuinely likes and respects them despite his gruff demeanor.
** He's also a very good cook, as indicated when he gives Catherine a recipe when she's debating what to prepare for her visiting in-laws.
** Goes all out to give Neela a nice going away party as a means of apologizing to her for the bigoted comments he made about her ethnicity and nationality when she first joined the staff.
* JerkWithAHeartOfGold: He's initially a {{Jerkass}}, but he gets better after his heart attack.
* SuspiciouslySimilarSubstitute: To Jerry.