Beware of Unmarked SPOILERS
Dr. Leanne Rorish (Marcia Gay Harden)
Angels Memorial's ER Residency Director, and a veteran emergency specialist with a reputation as something of a cowboy. She is a no-nonsense doctor with no patience for hospital protocol when a patient's life is on the line. Surviving the car crash that killed her husband and two children three years prior to the series has altered her previously warm and nurturing personality considerably and left her with a whopping dose of Survivor Guilt. Toward the end of season one she decides to take a leave of absence in order to properly grieve her family, only to be dragooned into service as the temporary ER Director before she can even get a foot out the door — much to her annoyance.
- Aloof Dark-Haired Girl: After the accident, she became considerably more aloof from just about everyone, with few exceptions.
- Awesome Ego: Leanne knows damn well just how good she is in the ER, and she isn't wrong — until the trauma of her past begins clouding her judgment. Uncharacteristic mistakes are what first cause her to re-evaluate and decide she really needs to actually start healing from her loss.Leanne: [to Hudson] You're the doctor they want. I'm the doctor they need.
- Birds of a Feather: She gets on famously with Ethan Willis right from the get-go due to their shared 'cowboy' attitude to medicine, and the two develop an almost sibling-like, teasing friendship and mutual trust as the episodes go on.
- Broken Bird: Very, very broken after losing her husband and two children, though she does start to heal eventually. Season two sees a much less prickly and more emotionally stable Leanne, though she never loses her no-nonsense demeanor.
- Character Development: By Season 3, she becomes considerably warmer thanks to the addition of Ariel in her life. She even becomes less of a cowboy in the ER, insisting patients be taken to the OR for more complex and delicate procedures because she isn't a surgeon, which wouldn't have been an issue in previous seasons.
- Defrosting Ice Queen: Her first season character arc focuses on her coming to terms with her family's deaths and opening up to other people. Taking in Ariel at the end of season two is a major signpost that she's ready to truly live again, instead of living in her memories.
- Dr. Jerk: She's initially very abrasive towards her colleagues and brutal towards her residents. Neal notes that this is actually a fairly recent development and that she was much friendlier and warmer prior to her accident.
- Family of Choice: After losing her whole family in a car crash, Leanne finds herself almost entirely alone. Then she meets Ariel Braeden as Ariel's father is dying, and a rather heartbreaking series of events later, takes Ariel in herself rather than sending her back into the foster system. It's made all but explicit that the two fit each other like puzzle pieces, giving them both someone to love and come home to.
- Friendly Enemy: Leanne has fierce debates with CEO Ed Harbert (her only true equal seen on the show) about administration, what she wants for her ER, and hospital policy, but she also exhibits a warmth with him that she shows to few other people. (Though he's far more 'antagonist' than 'enemy', being a truly good man with the hospital's welfare his foremost concern, he does get in Leanne's way quite a bit.).
- Like Brother and Sister:
Leanne: [speculatively eyes an incoming case at the end of her shift]Ethan: Don't even think about it. Go home.Leanne: [pouts, but actually leaves]
- Explicitly so with Neal Hudson, who reminds her to lean on him, too, because "that's what siblings are for."
- She also develops this dynamic with Ethan Willis, who becomes a close friend and confidante of hers.
- Mama Bear: Though she's "Daddy" to her residents, she's a more traditional Mama Bear to her eventual foster daughter, Ariel.Leanne: I'm not leaving her!
- Meatgrinder Surgery: She understands, better than most, that the ER's primary goal is to keep patients alive no matter how crude the methods. Surgeons like Dr. Campbell complain that her treatments tend to create secondary problems that need to be fixed in surgery but others appreciate the pressures the ER is under. It doesn't matter to Rorish because she's unapologetic about what she does.
- Papa Wolf: She will protect and defend her residents with everything she's got (even as she's tearing a strip off them in private, if necessary). This is a lesson some patients (and their family members) learn the hard way.
- Parental Substitute: She becomes this to Ariel Braeden, the daughter of a patient in the pilot episode who comes back into her life in season two and whom Leanne eventually ends up taking in permanently.
- Platonic Life-Partners: Jesse is her rock and her main source of support, and the most important person in her life after the fatal accident that killed her family. Neal Hudson actually has to remind her that there are other people she can count on.
- The Promise: Leanne promises Ariel that she will never lie to her, which turns the corner in their relationship and prompts Ariel to stop pushing Leanne away.Leanne: I will never lie to you. You can count on that. [cue Headbutt of Love]
- Red Oni, Blue Oni: She is the Red to CEO Ed Harbert's Blue, being much more openly passionate and willing to ignore the rules if she feels they're getting in her way.
- Screw the Rules, I'm Doing What's Right!: Her usual approach, when she even bothers to acknowledge that the rules exist at all.Leanne: Center Stage is where rules go to die.
- Sink-or-Swim Mentor: Averted. She expects her residents to jump in and handle horrific trauma cases from day one but she is also with them at every step, quizzing and guiding them through the various procedures and making sure no one is making any mistakes.
- Stern Teacher: She is incredibly tough on her students, but they all think the world of her (even when they curse her for making their lives difficult). They respect her enormously, and praise from her means more than praise from just about anyone else.
- Sugar-and-Ice Personality: Usually distant and icy, she can also be incredibly warm and nurturing — but don't point it out, or she'll snap right back to ice again. She softens up in season two, and is downright gooey with a vulnerable Ariel.
- Surgeons Can Do Autopsies If They Want: She frequently performs procedures that are supposed to be performed by highly-trained specialists in controlled operating rooms rather than a chaotic ER. This is thoroughly lampshaded throughout the show and she even admits that she shouldn't be doing them. However, there's often no time to wait and her knowledge and instincts are usually right so the rest of the staff just go along with it and don't report her.Dr. Carrie: You're not even a surgeon!Leanne: [drily] I get that a lot. [performs lifesaving surgery]
- Survivor Guilt: She suffers from a crippling case of this, unable to deal with the fact that she survived when the rest of her family didn't. It takes her a long time to learn to truly live again.
- Team Dad: Her primary responsibilities are to make sure her patients live and that her residents know how to do their jobs. She takes both immensely seriously and suffers no fools. If anyone needs a hug, Jesse is much more accommodating.
- Training from Hell: Everyone recognizes her as a very tough teacher who puts immense pressure on her residents. While Neal complains about it, Dr. Taylor brushes him off because her methods produce good doctors.
- Vitriolic Best Buds:
- With Jesse. They constantly snark at and insult each other to keep each other motivated.
- Similarly, her primary form of communication with Ethan seems to be snark, unless the situation is serious. He gives just as good as he gets.
- You Are in Command Now: She is abruptly dragooned by Ed Harbert to step in as ER Director after Gina Perello's death and before Mark Taylor's return from suspension, and is not happy about it. Ed is not particularly moved by her unhappiness and makes her do it anyway.
Nurse Jesse Sallander (Luis Guzman)
The ER's senior charge nurse. Everyone heavily relies on him for his experience and junior staff are expected to listen to his guidance. Doctors who try to throw their weight around with him quickly learn why they shouldn't.
- Beware the Nice Ones: He's normally very friendly and happy to joke around, but he will strike back a hundred times harder if someone disrespects him or any of his nurses.
- In-Series Nickname: He is known to just about everyone who works at Angels as 'Mama'.
- OOC Is Serious Business: The point during the epidemic when he can no longer volley insults with Leanne is the point when Leanne herself becomes genuinely scared, because she recognizes that it is very likely she is going to die. Fortunately, she lives.
- Platonic Life-Partners: With Leanne, particularly in the aftermath of her accident. He is her closest friend in the world and her chief source of emotional support.
- Real Men Wear Pink: He briefly works at a plastic surgeon's office and wears chartreuse scrubs as a uniform and seems to like the color. Other characters, however, very vocally express their distaste for his new style.
- Sergeant Rock: He holds this position within the ER hierarchy, in charge of all the nurses and heavily relied upon by all the doctors.
- Team Mom: He's the glue who holds the ER together, making sure that patients and staff are taken care of and alternating between supportive and stern when necessary.
Dr. Rollie Guthrie (William Allen Young)
A senior attending physician in the ER, and apparently the longest-serving physician in the department, having been there for well over thirty years. He is a much calmer presence, in direct contrast to Rorish, and prefers to take a more fatherly approach to mentoring the residents.
- Affectionate Nickname: He dubs Angus "Young Squire" while giving the younger man a friendly pep talk.
- Dark and Troubled Past: When a young resident, he came home one night to find his infant twins and his wife near death from a CO2 leak. He was able to revive his son Cole, but not his daughter Lola. The experience scarred him emotionally, and his wife eventually committed suicide out of grief. He blamed himself for being unable to save Lola or to recognize that his wife had become suicidal, and this also affected his relatonship with his son.
- "Unfinished Business" also implies that he lost his father at a young age.
- Hiding the Handicap: He keeps his Parkinson's secret from the rest of the ER, but Malaya and Jesse figure out what's going on.
- Parental Substitute: He becomes this to Angus, whose own father is rather distant, to the point where Angus occasionally calls him "Dad".
- Real Men Love Jesus: He is a deeply spiritual person and seeks comfort in his faith whenever he's troubled.
Dr. William Campbell (Boris Kodjoe)
Angels' Chief of Surgery, who has an enormous amount of pride in his work. He is openly disdainful of what goes on in the ER, believing that the doctors who work there are no more than butchers who do more harm than good for their patients, which brings him into conflict with Rorish and Hudson. A Board decision to combine the administration of Trauma One and the OR makes him the new ER Director in season 2.
- Bait-and-Switch Tyrant: While he still clashes regularly with the ER doctors, he eventually proves to be quite good at his job and earns their initially-begrudging respect.
- Dr. Jerk: His ego and disdain for others are both equally enormous.
- Insufferable Genius: Unfortunately for everyone who despises him, he really is that good of a surgeon.
- Interservice Rivalry: He genuinely despises emergency medicine and speaks down to everyone in the ER no matter their seniority. Fortunately, as Leanne predicted, serving as the ER Director humbles him considerably and gives him much more respect for the people who work there.
- Jerkass Has a Point: He frequently raises points from an administrative perspective that the ER doctors vehemently disagree with, but even they can't accurately say that he's wrong about some of them.
- Jerk with a Heart of Gold:
- Either he actually has a heart or spending so much time in the ER has corrupted him (or — quite probably — both), because season 2 sees him siding with Leanne in situations no one would have expected.
- As hardnosed as he is with the Angels Memorial staff, he shows a much softer side when around his daughter and shows a great deal of vulnerability when talking about her with Rorish.
- He was also uncharacteristically soft and sweet with Roseline, the Haitian girl with a spinal tumor seen in Season 1.
- Manly Tears: He is openly grief-stricken when Heather dies.
- Missing Mom: His wife walked out on him and their daughter after she couldn't cope with their daughter having spina bifida and the stresses of dealing with a condition that could kill their child at any moment.
- Nice to the Waiter: A primary indication that he isn't actually a terrible human being is the fact that he clearly respects his nurses, both in the OR and in Trauma One. He's not nice to them — or just about anyone else — but he treats them as competent medical professionals and never talks down to them.
- Not So Above It All: He pretends to be above such petty things as getting emotionally involved with patients and caring for his co-workers, but when he asks Jesse to return to Angels...Jesse: Say it.Campbell: I want my Mama back!
- Tyrant Takes the Helm: For budgetary reasons, the hospital Board combines the administration of Trauma One and the OR, making him the new ER Director. Needless to say, nobody in the ER is the least bit pleased with this decision — Leanne least of all.
Col. Dr. Ethan Willis (Rob Lowe)
An Army veteran who joins Angels after experience in an active combat zone. A roguish, blunt, rule-breaking cowboy, his "battlefield medicine" is catnip to Leanne Rorish but, predictably, doesn't go over well with some of the other doctors — most notably Campbell.
- Act of True Love: He moves heaven and earth to get Rox to the best neurosurgeon in the country after she's hit by a car and develops life-threatening complications. This is when everyone around him starts pointing out to his face that he's in love with her. He doesn't deny it.
- Birds of a Feather: He and Leanne get on like the proverbial house on fire, not least because they share a similar "cowboy" approach to medicine (in fact, he may even outdo her in this regard). As the season goes on, they develop a close, almost sibling-like relationship, teasing and supporting each other in equal measure.Leanne: You want to do it here?Ethan: I've done it in the back of a Humvee. Come on — you with me on this?Leanne: Game on.
- Chronic Hero Syndrome: Much like his dear friend Leanne, he has a compulsive need to save other people after he was unable to save his brother, Robert, in Afghanistan years earlier. Overcoming this is a major part of his character arc, as he learns that he doesn't always have to be the one doing the saving and that it's okay to need help.Ethan: [to Rox] I want you to save me.
- Combat Medic: He joins Angels specifically to help teach medical techniques developed on the battlefield to the civilian emergency doctors — this is the Army's Combat Casualty Care program, and it is very real.
- Commitment Issues: His love for Rox absolutely terrifies the bejeezus out of him. He gets over it, but not before they both cheat death several times over.
- Deadpan Snarker: He can get quite snarky when he thinks someone is being stupid. Or when he's in a snarkfest with Leanne. Or when Campbell is in the same room with him.
- Everyone Can See It: The list of people who are aware he is in love with Rox Valenzuela includes his father, Leanne, Rox's aunt Jae Eun, Campbell, Mario, Angus, Guthrie, random people who just met them, and Rox herself. It does not include Ethan, until almost all of the above start pointing it out to his face.
- Like Brother and Sister: He develops this dynamic with Leanne — there's no evident physical attraction between them, but they clearly care very deeply for each other and trust each other implicitly.
- Meatgrinder Surgery: You name a procedure, he's probably done it in the back of a moving Humvee. Possibly while also under fire. Needless to say, this is useful at Angels, to the point where Leanne starts looking to him for advice in particularly rough surgical situations.
- Reassigned to Antarctica: When asked if he's been sent to Angels as a punishment or a reward, Willis says that it's a mixture of both.
- Screw the Rules, I'm Doing What's Right!: He is basically the living embodiment of this trope, to the extent that he may actually exceed Leanne in this department.
- Shell-Shocked Veteran: It becomes increasingly clear that his coping mechanisms are... not all that healthy, and that his PTSD is a lot more serious than he lets on.
- Shrouded in Myth: When asked a question about his personal background, he gives an enigmatic one-sentence response. He eventually opens up to Dr. Nolan (Angels' staff psychiatrist).
- Unresolved Sexual Tension:
- His scenes with Amanda Nolan have fairly obvious sexual tension, though it never goes anywhere.
- Much more significantly, he has some serious chemistry with his paramedic partner, Rox Valenzuela — and this one actually goes somewhere.
- Vitriolic Best Buds: His primary form of communication with Leanne is snarkery, but the warmth in their relationship is obvious.
- War Is Hell: His major character motivation comes from his experiences as a doctor serving in Afghanistan. He learned of a young boy dying of appendicitis and successfully performed an appendectomy. Not long after, a military patrol found the boy on the side of a street, dead and with his stitches torn out as a warning from the Taliban. Willis took this as a challenge and treated every Afghan he could, disobeying orders from his superiors. When he was finally caught, he was removed from the frontline and sent to Angels Memorial as a punishment.
- Workaholic: Ethan spends his time off from his job... performing his job somewhere else. Naturally.Leanne: Another ride-along? You need a hobby.Ethan: Pot, kettle.Leanne: [grins]
Dr. Mario Savetti (Benjamin Hollingsworth)
An emergency attending physician who grew up in a bad home in a rough neighborhood in New York City and who sees ER medicine as his way out of his background. Much more aloof than his colleagues, he prefers to do things his way and steamrollers anyone who gets in his way. He slowly begins to loosen up, but retains his snarky personality.
Throughout the series' run he grows from being a first-year resident to a newly minted attending physician.
- Big Brother Mentor: He somewhat reluctantly becomes this to Ariel in season 3. It helps that, like Ariel, he had a troubled childhood, and that he will be absolutely straightforward with her — something Ariel clearly appreciates.
- Break the Haughty:
- Dr. Rorish immediately sees his superiority complex and makes a point of knocking him down a few pegs whenever possible because it's impossible to be a ER doctor if everyone else hates your guts. The lesson is very slowly getting through.
- Dr. Willis recognizes the same problem in Mario but takes a gentler approach than Rorish, telling Mario that he has all the skills to be a good doctor but that he needs to tone down his ego in order to be a great doctor.
- Daddy Issues: His father is a drug addict, alcoholic, and all-round terrible person, and Mario's worst fear is becoming his father.
- Dark and Troubled Past: He admits to having had a rough childhood, saying that his parents were neglectful to the point of forgetting about him for days at a time. He bonds with a patient over this because they both share a burning resentment of circumstances beyond their control and worked immensely hard to get away from their pasts.
- Friend to All Children: He is excellent with children, in part because he is willing to be bluntly truthful with them, but they also bring out a noticeably softer side to him. In particular, no one in the ER is better at calming scared young boys.
- Parent with New Paramour: In the wake of his father's death, his father's girlfriend, Linda, makes a valiant effort to get to know Mario. Mario is reluctant to let her into his life, but slowly he begins to warm up to her.
- Stepford Snarker: It's heavily implied that his cutting sarcasm is used primarily to mask his vulnerabilities.
- Vitriolic Best Buds: With Angus, who is either his best friend or worst enemy depending on the situation, but whom he eventually trusts even when he won't trust anyone else.
Dr. Angus Leighton (Harry Ford)
After originally pursuing a psychiatric residency, Angus used family connections to switch to emergency medicine, a choice he occasionally regrets. He slowly gains more confidence as a physician.
In Season 3, he switches specialties and takes on a surgical residency under Dr. Campbell's tutelage.
- Always Someone Better: This is how he feels towards his brother Mike, a well-regarded doctor who went through the same residency program. Mike, for his part, thinks that Angus can do just as well and wants his younger brother to become more self-assertive.
- Crouching Moron, Hidden Badass: When Angus forgets to doubt himself, he proves to be an extremely talented doctor. Unfortunately, he starts using Adderall to bring this out, with catastrophic results.
- Daddy Issues: His father has a very low opinion of him.
- Deadpan Snarker: Angus is probably the single kindest character on the show, but that doesn't mean he isn't usually ready with a snarky quip — particularly when Mario is involved.
- Dogged Nice Guy: Although Angus is a classic example of this trope, the relationship in question isn't - he spends a lot of the first season just trying to be friends with Savetti. By the start of the second season, they're Fire-Forged Friends.
- Heroic BSoD: Angus is sent spiraling after he intentionally lets Malaya's attacker bleed out. Among other things, this leads to his getting hooked on Adderall.
- Nepotism: He asked his father, a member of the hospital's board, to get him a ER residency. It is a decision he occasionally finds himself regretting, though he's proved on several occasions that he has what it takes to do the job and do it very well.
- Took a Level in Badass: He is much more confident in his abilities in Season 2, especially after standing up against his father in the wake of Mike's accident.
- Vitriolic Best Buds: Though he and Mario argue constantly, they are also rock-solid friends. Angus is the only one who can get through to Mario after his father's death, at which point Mario breaks down crying on Angus' shoulder.
Dr. Noa Kean (Emily Tyra)
A new first-year resident introduced at the beginning of Season 2. She skateboards as a hobby and is something of a loner, but always there for her colleagues when the chips are down.
- Deadpan Snarker: She's always ready with a snarky quip.
- Fiery Redhead: She definitely has a fierce temperament, signaled by her fiery red hair.
Dr. Elliot Dixon (Noah Gray-Cabey)
A new first-year resident introduced at the beginning of Season 2. He's rather naive at first and somewhat unsure of himself, but always incredibly kind and willing to help other people.
- Beware the Nice Ones: Don't get between him and what's best for his patients. Anyone who does will learn the hard way that under his sunshine-y personality is a backbone of steel.
- Embarrassing Nickname: Jesse nicknames him "Sugar Bear" on his first day, a nickname which sticks, much to Elliot's dismay.
- Foster Kid: Grew up in the foster system, though he still has a very kind and sunny attitude despite it.
- Hidden Depths:
- He has a talent for stand-up comedy that he gets a chance to show when his patient is a comedian. The patient is sufficiently impressed by one of Dixon's routines to promise him they'll work on it together after his surgery.
- He's fluent in American Sign Language, having learned it to speak with an ex-girlfriend.
- Naïve Newcomer: On his first day, he makes the mistake of asking Jesse where the lounge is. Jesse has him delouse a homeless man to teach him a lesson.
Paramedic Roxane "Rox" Valenzuela (Moon Bloodgood)
An experienced paramedic, Rox finds herself partnering up with Ethan Willis as he takes on more and more ride-along shifts in the knowledge that "the most vulnerable time for a patient is the time between trauma and a doctor." Initially thinking him too reckless, she reconsiders and agrees to join him in his efforts.
- Action Girl: As a paramedic, she often finds herself providing medical care in hazardous situations. She also served as a line medic with wildfire fire fighters, which just increases her badass.
- Brooding Boy, Gentle Girl: While she's definitely a firecracker, she tries to be this to Ethan. It takes him awhile to let her, though.
- Commitment Issues: Though she sorts hers out more quickly than Ethan sorts out his, she admits openly that the same thing that draws her to him (his Chronic Hero Syndrome) also terrifies her. She gets over it.
- Deadpan Snarker: She can match Ethan Willis in snarkery.
- Defrosting Ice Queen: She's no-nonsense and rather brusque, but it becomes evident that she has a much softer and more caring side.
- Everyone Can See It: Everyone knows that she and Ethan are in love with each other. So does she, actually, but she's so frustrated by his constant approach-and-withdraw Commitment Issues that she very nearly gives up altogether before he finally manages to actually confess his feelings.
- The Lancer: In much the same dynamic as shared between Neal Hudson and Leanne Rorish, she at least tries to temper Willis' cowboy tendencies before inevitably helping him out with whatever he's planning.
- Unresolved Sexual Tension: She has some fairly serious romantic chemistry with Ethan Willis, which evolves more into Ship Tease with every single episode.
- Will They or Won't They?: It's up in the air for most of the third season as to whether or not she and Ethan Willis will ever make a proper go of things, given his Commitment Issues — even though it's obvious from minute one that they're perfect for each other. They Do, eventually.
- You Called Me "X"; It Must Be Serious: She usually calls Ethan Willis by his last name, only using 'Ethan' when things are very, very bad.
Ariel Braeden (Emily Alyn Lind)
The daughter of a patient in the pilot episode, Ariel loses both her father and mother before she's twelve years old. Her return in the season two finale reveals that she's been in and out of juvie and essentially on her own, struggling to deal with her grief and find a stable home. She initially stays with Leanne until DCS can find her a group foster home, but a series of events results in Leanne taking her in for good.
- Aw, Look! They Really Do Love Each Other: Ariel is rather bratty in season two, but when she realizes she's going into quarantine, she throws herself into Leanne's arms and holds on until other doctors have to pull them apart, and when Leanne falls ill, Ariel is desperately worried about her and begs her not to die. Leanne, for her part, is a bit frustrated with Ariel's behavior but is incredibly tender with her nevertheless, even gently kissing her forehead at one point and being far more concerned for Ariel than for herself in quarantine.
- Bratty Teenage Daughter: She has a bit of an attitude problem in her return appearance, but it's made clear that she's just scared to get close to people because she might lose them — quite understandable given her background. After she finds a permanent home with Leanne, she settles down.
- Book-Ends: Ariel is the focus of both the pilot episode and the series finale.
- The Bus Came Back: Ariel wasn't expected to be seen again after the pilot, but she makes an unexpected return in season two.
- Character Development: She gradually becomes more confident and mature over the course of Season 3. In "Cabin Pressure," she plays an important part in helping a 12-year old girl trapped in a small plane to revive the unconscious pilot.
- Foster Kid: She initially goes to live with her aunt after her father dies, but that situation falls apart, and she struggles to find a caring home until Leanne takes her in.
- Happily Adopted: After Leanne permanently takes her in. Their love for and joy in each other is obvious and hard-won.
- Heroic BSoD: After Max dies.
- Like Mother, Like Daughter: It is plainly obvious that, like her mother, she is going to be an excellent doctor some day.
- Meaningful Echo: When Ariel has to be taken into the "hot zone" in quarantine, Leanne desperately cries "I'm not leaving her!" (though she's eventually forced to let her go). When Leanne herself falls ill, Ariel echoes the line, begging to stay with Leanne — and she does.
- Please Don't Leave Me: When Leanne finally succumbs to the hemorrhagic fever in "Fallen Angels", Ariel desperately tries to reassure Leanne and begs her to open her eyes. Leanne eventually does, but not before Ariel herself collapses (again).
- Trauma Conga Line: Her mother died when she was very young, her father died in "Pilot," she couldn't get along with the aunt who took her in and ended up in foster care, she nearly died from hemorrhagic fever, her first boyfriend Max died of cancer while awaiting a lung transplant, and then she ran away and fell in with a group of homeless, drug-using juvenile burglars.
Dr. Mike Leighton (Tommy Dewey)
- You can't tell anyone. Not your best friend, not your shrink. You and I take this to our graves. Agreed?
Dr. Rorish's temporary replacement as ER Residency Director. He went through Rorish's infamous training but is, himself, a much friendlier teacher than his mentor. He is also Angus Leighton's older brother.
- Always Someone Better: Angus feels this way towards Mike, who is extremely well-regarded and is handpicked by Rorish to be her replacement at a relatively young age. Mike, for his part, feels that Angus can succeed just as much once the younger man's confidence issues are resolved.
- Big Brother Instinct: He is very protective of Angus.
- Big Brother Mentor: He's a lot friendlier and more nurturing than Rorish as ER Residency Director, preferring to soothe the panic in the ER as opposed to how Rorish feeds off of it to keep the residents on their toes. He's also literally this towards Angus since they're siblings.
- Convenient Coma: He becomes comatose after falling out of a helicopter in the Season 2 premiere and Angus is given power of attorney over Mike's major healthcare decisions.
- Put on a Bus: After his not-so-convenient coma, he deals with aftereffects so severe that he is at least temporarily unable to practice medicine. (In real life, this was because Tommy Dewey had other commitments and couldn't become a regular.)
- Secret Keeper: He's the only one who knows that Angus essentially murdered someone and swears that the two of them will take the secret to their graves. See quote above.
Dr. Ed Harbert (Jeff Hephner)
Angels Memorial's CEO. He has experience as an ER doctor and has kept his license up to date even as an administrator. His more cynical, business-oriented approach brings him into conflict with Leanne Rorish, but he also teaches her a few hard truths about the practicalities of administration and repeatedly proves to have Angels' best interests at heart.
- Absentee Actor: There are several episodes in season 2 where Harbert could quite reasonably have been expected to make an appearance, but didn't; this is because his actor, Jeff Hephner, was working full-time on a different show.
- Beleaguered Bureaucrat: He has to balance the demands of over a dozen different departments on a shoestring budget (a very frayed shoestring) while trying to keep the donors (responsible for a sizable amount of Angels' funding), Board, department heads, and staff happy. Though he rarely shows the strain, scenes with Leanne make it quite clear that this wears on him.
- Foil: He was deliberately written to be this to Leanne — a qualified doctor with a very different approach to hers, and also her absolute equal. He is the only person so far seen on the show who is actually capable of going toe-to-toe with her at full strength and winning.
- Grave-Marking Scene: He visits Gina Perello's grave with a bouquet of daisies, telling Leanne that they were her favorite flowers.
- Honest Corporate Executive: His priority is and always will be protecting the hospital, though sometimes that means doing things his staff (and especially Leanne) don't like. He's budget-conscious, analytical, and willing to woo donors and exploit loopholes to increase funding, but he has very good reasons for this.
- Nice Guy: He may be a dyed-in-the-wool cynic, but he is an undeniably good, kind man.
- The Quiet One: He only speaks when he really has something to say, which means that when he talks, even Leanne listens.
- Reasonable Authority Figure: He is one, with his foremost priority being to protect Angels and its staff and to do his best by the hospital. Even Leanne "Rules? What rules?" Rorish has to admit that he's good at his job and, more importantly, on the side of the angels.
- Red Oni, Blue Oni: His cynical, numbers-oriented, budget-conscious approach is a stark contrast to Leanne Rorish, as is his perpetually cool, competent, unruffled demeanor.
- Secret Relationship: He was romantically involved with locum ER Director Dr. Gina Perello, a fact which only comes out after her death. Leanne runs into him quite by accident while visiting Gina's grave, and realizes that he is genuinely distraught at losing her. Given what Leanne herself has been through, her condolences are utterly heartfelt and understanding.Leanne: ...I didn't know you were seeing her. I'm sorry for your loss.
- The Stoic: He is steady, levelheaded, and near-perpetually unruffled, taking everything that comes his way with calm, cool deliberation. Not even Leanne Rorish on a tear can really throw him. This makes his visible grief at Gina's grave even starker in comparison.
- Stoic Woobie: He had to head a Board inquiry into his girlfriend's violent murder (in his hospital!) while remaining calm, cool, collected, and impartial. Just to make it worse, nobody knew they were involved, so the ER staff being interviewed hated him a little bit for doing his job.
Dr. Amanda Nolan (Kathleen Rose Perkins)
A psychiatrist at Angels Memorial, introduced in season 2.
- Action Survivor: She holds herself together rather well during a crisis, but she's still badly shaken by the experience and doesn't play the hero. Quite understandably, given her lack of experience in that area.
- One of Our Own: She is injured in a haunted house collapse in "Demons and Angels"; Ethan has to relocate a dislocated rib.
- The Shrink: She's a psychiatrist, and good at it if the way she reads Ethan Willis is any indication.
- Unresolved Sexual Tension: Her scenes with Ethan Willis have visible sexual tension, though it never goes anywhere.
Dr. Neal Hudson (Raza Jaffrey)
Originally an attending ER physician. Rorish's diametric opposite in terms of personality but just as passionate about saving lives and making sure the residents learn how to do their jobs. He originally trained to be a surgeon before switching specialties. Towards the end of the first season, he switches again and becomes a surgical attending after repeated clashes with Dr. Campbell leads to a desire to practice medicine with more finesse.
- The Lancer: For Rorish.
- Like Brother and Sister: His relationship with Leanne is rather big sister-little brother, to the point that he sometimes reminds her to lean on him because "that's what siblings are for".
- Screw the Rules, I'm Doing What's Right!: Not his usual mode of operating, but he's willing to go there if the patient needs him to (or if Leanne asks him to).
- "Well Done, Son!" Guy: His father, a neurosurgeon and elite medical researcher, thinks Neal shouldn't be doing something so mundane as emergency medicine.
Dr. Christa Lorenson (Bonnie Somerville)
A resident who began her medical career later in life after her son died of cancer and her marriage fell apart as a result. She is the most sincerely idealistic of the ER staff, having decided to become a doctor out of a genuine desire to help rather than ego and/or family expectations.
- Dark and Troubled Past: Her young son died of cancer, and the stress of his illness destroyed her marriage.
- Hair of Gold, Heart of Gold: She is the only true blonde among the main cast, and also the most openly emotional and kindhearted.
Dr. Cole Guthrie (Cress Williams)
Dr. Rollie Guthrie's son, a talented surgeon with some serious Daddy Issues.
- Dark and Troubled Past: His mother killed herself when he was a child, and he's the one who found the body.
- had a twin sister who died in infancy. His sister's death precipitated his mother's mental illness and eventual suicide.
- The Bus Came Back: Season 2's "Unfinished Business."
Dr. Gina Perello (Christina Vidal)
An administrator and doctor who stepped in as ER Director while Mark Taylor was on a two-month suspension. Though initially abrasive and by-the-book, her time at Angels taught her that some rules need to be broken at times. She is killed in the same violent event that resulted in the sexual assault and stabbing of Malaya Pineda, sparking a Board inquiry and traumatizing the entire ER.
- Reasonable Authority Figure: She proves to be one eventually, as she is willing to put the good of the patients above the rules at times and has her reasons for insisting that protocol be followed as much as possible.
- Secret Relationship: She was romantically involved with Angels CEO Ed Harbert, a fact which is only revealed after her death.
Dr. Mark Taylor (Kevin Dunn)
Angels Memorial's Director of Emergency Medicine. He doesn't particularly care for his people's personal problems because he expects them to focus on the work at hand rather than any drama and because he has more pressing budgetary and political issues to deal with. He gets placed on a two-month suspension midway through the first season.
- Beleaguered Bureaucrat: His job is mainly administrative and the workload is crushing because Angels Memorial has the busiest ER in the country while the budgets are constantly being slashed. This means he has very little patience for any interpersonal conflict among his staff and expects them to focus on the patients rather than their own issues.
- Dr. Jerk: He is quite rude and blunt and can occasionally launch into loud and inappropriate stories in the middle of the ER if there's a conflict between staff. This is done out of a belief that doctors and nurses should just shut up and do their jobs and leave the personal drama at home.
- Reasonable Authority Figure: For all his quirks, he will back his department to the hilt, and proves himself a dozen times over when Neal Hudson's mother Asra, among others, winds up in quarantine with a suspected respiratory contagion and Neal is the doctor in charge of treating all its victims. As Taylor puts it, the "full resources of [Angels]" are at Neal's disposal — and he means it.
Dr. Charlotte Piel (Nafessa Williams)
An actress, famous for her role as "Jessamine" in the ''Artemis'' film franchise, who has gone to medical school. She is introduced in the Season 2 premier, "Second Year." Later in that season, a disgruntled man drew a gun in the hospital and his gun went off in the ensuing chaos. Charlotte, unfortunately, was hit by the bullet trying to protect civilians and bled to death on Halloween night. A memorial was erected outside of the building to honor her sacrifice.
- Badass Bookworm: She graduated from medical school at the top of her class and has textbooks memorized to the point that she can cite exact pages off the top of her head.
- Heroic Sacrifice: She is killed by a stray bullet while shielding a young girl in the ER waiting room.
- I Just Want to Be Normal: see quote above.
- Non-Idle Rich: She used the money she made as an actor to pay for her schooling.
Dr. Heather Pinkney (Jillian Murray)
A surgical resident under Dr. Campbell's instruction, and one who is very good at her job. She is much friendlier than her mentor but almost always takes his side in an interdepartmental dispute. She's somewhat promiscuous and has had simultaneous sexual relationships with Campbell and Savetti and is implied to be sleeping with others as well.
She is infected with, and subsequently dies of, hemorrhagic fever in the first half of the Season 2 Finale.
- Blackmail: She uses the bedroom selfies from her affair with Campbell as leverage against him.
- Break the Haughty: When her blind ambition gets to be too much to bear, Dr. Campbell promptly cuts her off at the knees and relegates her to the most basic of tasks until she's suitably cowed.
- Functional Addict: She is apparently dependent on Adderall but, unlike Angus, appears to still be able to do her job... so far.
- Jerk with a Heart of Gold: She is ruthlessly ambitious and can be quite cruel, but she also has a much softer side; for instance, she gives Angus Adderall out of a genuine desire to help him, and she sincerely reassures Campbell when his daughter has to undergo surgery.
- Really Gets Around: She was explicitly sleeping with Campbell and Savetti around the same time and is implied to be sleeping with a number of other people as well.
- Small Name, Big Ego: She is an excellent surgical resident and knows it, resulting in an overinflated ego. She is blatantly careerist, to the point of neglecting her duties to run off and take part in a dangerous rescue operation because she thought she could get a juicy research paper out of it. Dr. Campbell finally has enough and punishes her until she realizes that her responsibilities to her patients trump her ambitions as a doctor.
Dr. Malaya Pineda (Melanie Chandra)
A perennially cheerful emergency resident eager to show off her knowledge and skills. She did med school and her internship at Angels, unlike her year-mates; therefore she knows the hospital and its staff better than they do, and becomes a source of support for Angus in particular.
- Lipstick Lesbian: She's openly gay and apparently the only character with a social life outside of work.
- Out of Focus: In season 2, she was less prominent than her fellow residents Mario and Angus, though she was still a regular character.
- Put on a Bus at the end of Season 2.
- Teacher's Pet: She's the most eager to prove herself in the ER, although Jesse keeps telling her that she shouldn't try and force herself into the limelight.
- Trauma Conga Line: Her Season 1 arc. Her ex-lover dies of inoperable cancer (after giving birth), and then she gets attacked and stabbed by a stalker.