First appearance: A Hard Day's NightDerek (Patrick Dempsey) and Meredith Grey (Ellen Pompeo) meet at a bar and go home together without realizing that she will be working with him at the hospital.After Meredith wakes Derek by dropping a pillow on him, he picks up a piece of her clothing and says, This is …She grabs it back from him and insists she has to get ready for work.Last appearance: Good as HellDerek dies in a fatal car accident when he receives poor medical care at a hospital. His death severely impacts Meredith, who is pregnant with his child.He is often referenced as a world-class surgeon and the love of Meredith's life. During season 17, he appears in a dream-like beach scene with Meredith when she is severely sick with COVID-19.His very last line spurs Meredith to wake up from her coma when he says, You have to go.First appearance: A Hard Day's NightCristina (Sandra Oh) speaks her first line to Meredith on their first day as interns.After Meredith comments on how few women are in the surgical program, Cristina says, Yeah. I hear one of them's a model. Seriously, like that's going to help with the respect thing?It is later revealed that Izzie (Katherine Heigl) is the model, and although Cristina originally dislikes her, she ends up being the maid of honor at Izzie's wedding a few years later.Last appearance: Fear (of the Unknown)Although Cristina became a well-respected heart surgeon in Seattle, her connection to Grey Sloan Memorial, where Jackson Avery (Jesse Williams) sits on the board, prevents her from rightfully winning the prestigious Harper Avery Award, so she leaves the hospital.Settled into her new office in Switzerland, Cristina is told people are ready for her and says, Let's do it, closing the door with her name on it behind her.First appearance: A Hard Day's NightWhen George (T. R. Knight) hears that Meredith and Cristina have also been assigned to Bailey (Chandra Wilson), he joins in their conversation.He tells them that he'll be working with Bailey too, and introduces himself before telling Meredith that he remembers her from the intern mixer.Last appearance: You'll Never Walk AloneGeorge saves a woman from being run over by a bus but is fatally injured when he is hit instead.His death has a significant impact on every doctor at the hospital, as he was well-liked by many and was the only person from Meredith's core intern group to die.When Meredith is severely ill from COVID-19, she imagines walking on a beach and talking to George.His last line is How do you figure? before Meredith tells him that his selflessness has changed her life.First appearance: A Hard Day's NightFrom her very first line, Izzie (Heigl) shows her optimistic attitude when she tries to defend Bailey.The interns have heard that Bailey is a harsh resident to work with, but Izzie says, Maybe it's professional jealousy, and insists that Bailey could end up being brilliant and nice.Last appearance: I Like You So Much Better When You're NakedWhen Meredith finds Izzie packing up her stuff, she begs Izzie to stay by saying Seattle is her home.Izzie replies, No, it's not. Not anymore. It's just a place I worked, and I can do that anywhere.Even though that is Izzie's last spoken moment, another actress plays her stand-in during Leave a Light On, the episode that reveals Izzie used the embryos she and Alex (Justin Chambers) had frozen to have his twins. When he finds out, Alex then goes to live with her and raise their children together.First appearance: A Hard Day's NightPreston Burke (Isaiah Washington) already has a reputation for being a fantastic heart surgeon at the start of the show.He says, What do we got? A wet fish on dry land, about a patient when he walks into the room. Last appearance: We Are Never Ever Getting Back TogetherBurke leaves Seattle Grace Hospital after standing up Cristina at their wedding.He continues to be a successful cardiac surgeon and has set up his own practice in Switzerland.In his last scene, he offers his entire hospital to Cristina since he wants to retire and spend more time with his family, saying, This place is yours, Cristina, if you want it.First appearance: A Hard Day's NightKatie (Skyler Shaye) — a teenager who competes in beauty pageants and keeps having seizures — is Meredith and Derek's first patient together.Though Meredith saves her life after diagnosing her with an extremely rare condition, Katie dislikes her at first. Her very first line is, You're lost, after realizing Meredith got lost in the hospitalLast appearance: My ShotKatie appears in two other episodes throughout the series.During season 12, another aneurysm brings her back to the hospital, and Amelia works on her since Derek has died by then.Her last appearance is during season 16 when Katie speaks on behalf of Meredith at a trial. Her final lines are, On Dr. Grey's very first day as a doctor, she was the only one that could figure out what was wrong with me. And because of her, I am sitting here, with a newborn baby girl at home, and I just hope that I can give her back a little of the help that she gave to me.First appearance: A Hard Day's NightAt the beginning of his internship, Alex (Chambers) is rather rude to the doctors that will eventually become his best friends.When George makes a mistake during surgery, Alex says, He's 007, implying that George is likely to kill the patient.This nickname ends up being extremely important — when George is dying, he is severely disfigured and cannot speak so he traces 007 into Meredith's palm to tell his friends who he is.Last appearance: Leave a Light On By his last season, Alex is the only doctor besides Meredith from their intern group who is still in Seattle.On his final episode, he's heard in voice-overs as the other characters read the letters he left for them about why he won't be returning to Grey Sloan. Bailey reads her note last, and his finals lines in it are: Goodbye and thanks. I love you, Dr. Bailey. — Dr. Alex Karev.First appearance: A Hard Day's NightBefore Ellis (Kate Burton) appears on-screen, viewers already know that Meredith's mother is a legendary surgeon who used to work at Seattle Grace.Her first lines don't happen until the very end of the pilot episode, when Meredith tells her about her first day as an intern.After listening to Meredith talk, Ellis turns to her and asks, Are you the doctor?She has a few other lines in this heartbreaking scene that reveal she doesn't understand who Meredith is and is dealing with advanced Alzheimer's.Last appearance: Blood and WaterAlthough Ellis dies during season three, she appears on several episodes after in flashbacks and dreams. In her last, she is suspicious of Amelia Shepherd (Caterina Scorsone), Derek's sister. Meredith wakes up immediately after Ellis says, Don't forget to take your vitamins, dears.First appearance: Who's Zoomin' Who?Though Addison's (Kate Walsh) first line is about Derek not returning her calls, the most memorable one in her first scene is, You must be the woman who's been screwing my husband, which she says to Meredith.Her introduction in the season-one finale is the first time that viewers and Meredith find out Derek is married.Last appearance: If/ThenAfter several seasons on Grey's Anatomy, Addison Montgomery leads the ABC spin-off show, Private Practice.She returns to Grey's for If/Then, an episode that shows where characters would end up if they made different choices.Addison's last lines are part of an argument she has with Derek in this alternate universe when she implies that he doesn't love her and says, It isn't your baby. First appearance: YesterdayWhen Mark (Eric Dane) arrives at Seattle Grace Hospital, it's revealed that he was Derek's best friend but also the man he caught in bed with Addison.Mark says, Invasive non-small cell with a history of C.O.P.D. Guy's pretty much a goner, huh? to Meredith as he reads a patient's file and starts flirting with her.Their conversation comes to an abrupt halt when Derek punches him in the face.Last appearance: BreatheMark sustains serious injuries during the plane crash that kills his partner and Meredith's sister, Lexie Grey (Chyler Leigh).Although he makes it to Seattle Grace Hospital to be treated, he eventually dies after a few moments of being alert.Alongside Lexie, he later appears in Meredith's beach dream she has while sick with COVID-19. Referencing life, he says, Don't waste one single minute.First appearance: YesterdayWhen Ellis Grey is hospitalized, her Alzheimer's causes her to mistake George for her ex-husband, Thatcher (Jeff Perry).After having heard about him throughout the series, Thatcher makes his first appearance when Meredith shows up at his house.His first lines are surprised responses to the questions Meredith begins asking about his relationship with Ellis, before he asks Meredith if she needs anything.Last appearance: The Winner Takes It AllMeredith and Thatcher have a strained relationship throughout the show.Early on, Meredith resents him for having abandoned her, and after Thatcher's new wife dies at Seattle Grace, he blames Meredith and even slaps her.Despite the issues between them, Meredith still donates part of her liver to him after his is destroyed from alcohol abuse.Although they lose touch for a few years, Meredith reaches out to him before he dies, and his final moments are spent telling her that he wishes he had gotten to know her children.Meredith puts her hands on his face, and he tells her they are cold. When she offers to remove them, he says, No, no, no. It feels good. She then proceeds to tell him about her kids.First appearance: What Have I Done to Deserve This?Callie (Sara Ramirez) is first shown helping fix George's dislocated arm after he falls down a set of stairs.She says his name and immediately recognizes him as the heart in the elevator guy, since George had previously performed heart surgery on a patient while trapped in an elevator.Last appearance: Family AffairAfter marrying and divorcing George, Callie marries Arizona Robbins (Jessica Capshaw) and has a child with her and Mark. But during her last season on the show, Callie decides to move to New York with her new girlfriend, Penelope Blake (Samantha Sloyan).Callie and Arizona have a custody battle, and in their last on-screen conversation, Arizona agrees to equal time with their daughter. Teary-eyed, Callie says, Thank you.First appearance: Testing 1-2-3Lexie (Leigh) first appears at the bar near the hospital. When she spots Derek, she approaches him and says, Hi. Can I buy you a drink? then mentions that she's had a bad day.It isn't revealed until later that she's Meredith's half-sister.Last appearance: BreatheLexie is seriously injured during the plane crash that also kills Mark.When she realizes that she's dying, she asks Mark to tell her father and Meredith that she loves them before asking Mark to hold her hand.Although that was the last viewers had seen of her for a while, Lexie appears in a beach dream with Mark when Meredith falls ill with COVID-19. Lexie last says, Don't waste it, Meredith, talking about life.First appearance: Wish You Were HerePediatric surgeon Arizona (Capshaw) has her first lines while introducing herself to Bailey.Arizona has been hired after another pediatric doctor died, and Bailey is initially bothered by the way Arizona wants to change a child's course of treatment.Arizona glides away on her wheeled shoes after she finishes her first scene.Last appearance: All of MeBy the time she leaves the show, Arizona has married and divorced Callie and survived the plane crash that killed Lexie and Mark.Arizona decides to go to New York to raise her and Callie's daughter, Sofia.In her last moments, she talks to April (Sarah Drew) and tells Sofia they should help clean up from what was supposed to be a wedding ceremony, adding, Hey you know what? Let's go get her some water.First appearance: InvasionJackson (Williams) starts working at Seattle Grace after it merges with his former hospital.He references his past experience in his first lines during a hectic moment, saying, At Mercy West we do zones. When it's super busy, we just give everyone a zone, a space, which impresses Owen Hunt (Kevin McKidd).Last appearance: Someone Saved My Life TonightAfter Jackson treats patients who were injured at police-brutality protests, he decides to move to Boston and lead the Catherine Fox Foundation to help underserved communities often overlooked by the healthcare system.On a video call with Jo Wilson (Camilla Luddington) — who's in a new, unfurnished apartment — he says, Alright, I gotta get back to work. Welcome home, Jo.First appearance: InvasionApril (Drew) is also a former Mercy West doctor when she first appears.While Lexie is showing her around, April says, Thanks for being my tour guide through all this first-day madness.She then mentions hearing about dangerous procedures that Lexie and her friends had done.Last appearance: Look Up ChildApril is last seen talking to Jackson, her ex and former coworker, about his decision to move to Boston. She agrees to move with him so they can both raise their daughter together. At the end of the conversation, she says, Fingers crossed for new horizons.First appearance: Going, Going, GoneShane (Gaius Charles) is part of Stephanie Edwards (Jerrika Hinton) and Jo's intern class.When Bailey asks how long a patient's calcium levels should be monitored, Shane answers, Every 12 hours.Last appearance: Fear (of the Unknown)After years of working in Seattle, Shane decides to move to Switzerland with Cristina so he can continue learning from her.His last line is spoken in her new Zürich office. He says, Dr. Yang? They're all ready for you.First appearance: Going, Going, GoneStephanie (Hinton) is also an intern during her first season.Jo approaches her asking for a favor, and before she hears what it is, Stephanie says, No.She then adds that she knows what Jo wants and that she won't go anywhere near Medusa for you, referencing Meredith. Last appearance: Ring of FireStephanie's last episodes show her going to impressive lengths to save a young girl from a dangerous patient and the fire he caused. The experience makes Stephanie realize that between the illness she experienced as a child and all of her years dedicated to surgical training, she has spent her entire life in hospitals.While severely injured in a hospital bed, she tells Webber (James Pickens Jr.) that she quits, then says, OK, DeLuca, turn that morphine up as high as it'll go, please.First appearance: Time StopsAndrew (Giacomo Gianniotti) is first shown when he comes in on an ambulance with a patient, making him late for his first day as an intern.He says, Her name is Joan Paulson. She's 40 weeks pregnant and in active labor.He then introduces himself as a surgeon and not an intern, but his lie becomes apparent when he's unable to help the patient on his own.Last appearance: In My LifeDeLuca was stabbed after tracking down a sex trafficker on the ABC spin-off show, Station 19. After being taken to Grey Sloan Memorial, he died in the operating room from losing too much blood during the episode Helplessly Hoping.However, he is last seen on-screen during Teddy Altman's (Kim Raver) PTSD-fueled dream sequence and tells her he forgives her. She says that maybe it isn't too late to save him since he's here, and he replies, But I'm not.First appearance: Go Big or Go HomeKoracick (Greg Germann) comes to Grey Sloan when Amelia asks him to consult on her brain tumor.As Amelia updates him on the vital information, he says, Ah, slow down. Who's he? in reference to a resident in the room.Their conversation then reveals that he was the surgeon who taught Amelia.Last appearance: TraditionDuring the latest season, Koracick contracts COVID-19 and nearly dies.He's shaken by how many of the patients he had been in rooms with died from the virus, most of them not white.Trying to cope with survivor's guilt, he asks Jackson if he can go to Boston with him and work for the Catherine Fox Foundation. When Jackson agrees, Koracick says, Avery, thank you.