Full disclaimer: We might disagree on what enneagram type these characters are, but this is only my opinion! (btw I'm only on season 8).
1. Miranda Bailey
Bailey is a rule follower, and she is a very principled person. However, she is a very opinionated person. I mostly see her as a Type 1 only because she is such a do-good person, specifically in her professional life.
2. Teddy Altman
Type 1: I had a hard time trying to figure out what type Teddy would be. It was either between a 1 or 6, and I chose 1 just because I feel like she has a perfectionist style to her surgeries and within her job.
3. Derek Shepherd
Type 2: Yes, I do think Derek is a 2. Only because of how he treats his patients and how much he cares about his job and everyone who is effected by what he does.
4. Lexie Grey
Type 2: Lexie loves to be told she's doing a great job and she's possessive over her loved ones, especially Mark. Also, you can't argue that she isn't the most generous and caring character on the show.
5. Cristina Yang
Type 3: I honestly don't see her as any other type. Her achievements define her and she would probably physically die if she wasn't excelling in her surgeries.
6. Preston Burke
Type 3: I know I'll get mad hate for this one, but tell me Burke didn't care about his achievements just as much as he cared about Cristina? He's low key conceited.
7. Meredith Grey
Type 4: If this type doesn't scream Meredith Grey, I don't know which one does! She is pretty dramatic, I'm not going to lie. And not to mention her temper... but, if the shoe fits. I know she might be your favorite character but you can't deny the facts.
8. Jo Wilson
Type 5: No one hate me on this one... I don't know who Jo is yet but from what I've researched on her she's a type 5. Point. Blank. Period.
9. Owen Hunt
Type 5: For all you Owen lovers, sorry but I can't stand him. But I think he's such an isolated person and he keeps secrets from everyone. We dislike a lying man.
10. Jackson Avery
Type 6: I might be biased on this one because I'm a 6 but Avery isn't a problematic person in the series. He's caring but is also committed to what he cares about. However, he is anxious and unsure of his skills. A perfect 6.
11. George O'Malley
Type 6: George was good. He was loyal to his job (but not with Callie, but we're not going to talk about that.) George was always ready to learn, just like a 6.
12. Arizona Robbins
Type 7: Of course the head of Peds is a type 7. She has to have that outgoing personality for those tiny humans.
13. Callie Torres
Type 7: Yes, I think Torres is a type 7. She loves life and she loves to have fun. Why wouldn't she be a 7?
14. Alex Karev
Type 8: Karev is a dick, don't lie to yourself. He can be a sweetheart deep down but he's aggressive, overly confident and confrontational. That screams type 8.
15. Mark Sloan
Type 8 I think the best part of Sloan is his type 8 personality. He's confident in his abilities, power, gets stuff done and very dominating. We love Sloan for that.
16. Addison Montgomery
Type 8: She's confident in her profession but maybe not herself. But she is powerful, try telling me you wouldn't be intimidated by her irl..
17. Richard Webber
Type 9: Chief is a good teacher and a peacemaker. He's an easygoing guy even though he gets on my nerves sometime. But he is for sure a 9.
18. Izzie Stevens
Type 9: I think Izzie is a little bit of a 2 and a 9, but she's reassuring to all her patients and coworkers. Still kinda upset that she left..
19. April Kepner
Type 9: Kepner is annoying let me tell you that, but she's an easygoing gal despite how annoying her voice is.