Today, many will agree that ABC’s Grey’s Anatomy is one of the best medical dramas airing right now. Having been around since 2005, it also happens to one of the longest running television shows of all time. Created by Shonda Rhimes, the show has always been known to intertwine personal issues with medical complications, which results in interesting television.
Aside from its main cast, the show has also seen several famous actors make a couple of guest appearances as either the characters' relatives or as patients. However, with seventeen seasons under its belt, it's possible one may not have caught them all.
Sarah Paulson
While guest actors on the show often portray patients or someone related to them, there is the odd occasion that they can also play one of the main characters. This was the case for Paulson as in the season six flashback, "The Time Warp," she played a younger version of Meredith’s mother, Ellis Grey.
The episode finally answered some questions for fans regarding Ellis’ affair with Webber. However, if fans were hoping for her return, they will be highly disappointed. In recent years, Paulson has been a regular fixture in the series, American Horror Story, where she’s known for playing several characters, Cordelia, Lana Winters, and Billy Dean.
Mandy Moore
In Grey’s Anatomy, Moore played the role of a patient named Mary. She first appeared in the season six episode, "Sanctuary," where the hospital was forced to go on lockdown due to an active shooter in the building.
The actor reprised her role in the season seven episode, "That’s Me Trying," where she ended up in a coma after a complication in her surgery. Fans would agree that Moore delivered quite a performance during her short stint on the show. Sadly, however, some people have argued that it wouldn't rate as Moore’s best performance.
Hector Elizondo
Elizondo joined the cast briefly as the father of Dr. Callie Torres, a character who’s had one of the more interesting story arcs of the series. As many fans know, Callie and her father had a pretty close relationship. However, their relationship became briefly strained when Callie revealed that she was bisexual and in a relationship with Arizona.
Elizondo's character was seen to be against the relationship at first. However, he does learn to accept his daughter for who she is when he refuses to disown her for marrying Arizona. One could truly see that he wanted the best for his daughter.
Seth Green
While most people have often seen Green in comedic roles, such as Austin Powers and Rat Race, Grey's provided him something different. Something that was a little more serious role and allowed fans to see him at his full potential. Some fans may remember that Green played a patient called Nick, who was admitted to the hospital with a tumor in his carotid artery ("Crash Into Me").
While he was there, he was also seen to strike up a bond with Lexie. However, this didn't last very long as a complication arose after his surgery and he sadly bled to death. Since then, Green has continued to do a lot of voice acting for Family Guy and Robot Chicken.
Geena Davis
When it was revealed that Academy Award winner Geena Davis joined the show, fans were excited to see what was in store for her. They soon learned that Davis would play fetal surgeon, Dr. Nicole Herman. While most of her arc was seen to be mentoring Arizona, fans were soon shocked to discover that she had been diagnosed with an inoperable tumor.
After the other surgeons hear of her diagnosis, Herman decides to Amelia up on her offer to have the surgery. Although the procedure leaves her blind, Herman was still delighted as it meant that she would now survive. Davis eventually made one last reappearance in season 14 when she proposed to Arizona that they should open a health center together.
John Cho
Cho appeared in the season two episode, "Damage Case," as Marshall Stone. After finishing a shift at Mercy West, Marshall fell asleep at the wheel and was involved in a major accident. While Marshall was lucky to only sustain a concussion, the occupants of the other car weren't so fortunate.
One of the victims ended up succumbing to her injuries, which leaves Marshall guilt-ridden. Since then, Cho hasn’t reprised his character. However, over the years, he has also done a lot of work on the big screen.
Chris O’Donnell
Today, O’Donnell is widely recognized for his role as NCIS Agent G. Callen in CBS’ NCIS: Los Angeles. However, there was a time when O’Donnell appeared for a recurring role in Grey’s Anatomy. In this medical drama, he portrayed Finn Dandridge, a veterinarian who also became Meredith’s love interest.
The actor was asked several times to stay for more episodes, but he told Entertainment Weekly, “From a business standpoint, it wasn't going to be a success for me.” Nonetheless, his portrayal of Finn is considered one of his best works.
Millie Bobby Brown
Most people would commonly associate Brown with Netflix’s Stranger Things and Enola Holmes. However, way back before she was on the show, Brown appeared in this medical drama as a little girl named Ruby in the season 11 episode "I Feel the Earth Move."
The actress later on admitted that she knew little about the show around this time, just that it was really popular. “When I was in it, I kind of knew that it was a big deal,” Brown told Interview. “My sister’s a big fan so I kind of knew.”
Tessa Thompson
On Grey’s Anatomy, Thompson was cast to play Dr. Webber’s niece, Camille, who was diagnosed with ovarian cancer. The actress went on to appear on show’s season two for two episodes. However, the role was eventually recast as Thompson went on to become a bonafide film star.
Since last appearing in Grey’s Anatomy, Thomspon was has appeared in several Hollywood blockbusters. She was cast as the Asgardian, Valkyrie, in Marvel's Thor: Ragnarok and Avengers: Endgame. Not only that, but the actress also joined her MCU co-star Chris Hemsworth in the most recent Men in Black film.
Leslie Odom Jr.
Odom’s small role occurred way back in season five, where he portrayed P.J. Walling. In this episode, P.J. agrees to donate a kidney to another patient after his estranged father offered to pay him $10,000.
However, the two men managed to repair their relationship after P.J. realized that his father was seriously ill, refusing to leave his bedside. Since making a brief appearance in the medical drama, Odom has gone on to star in Broadway hit Hamilton where he sings one the catchiest songs of the show.