A Guide For the New and Returning Characters in "Grey's Anatomy" Season 19

Williams reprised his role as Dr. Jackson Avery on the Nov. 3 episode of season 19, "When I Get to the Border," which he also directed. "I love the family that I have on that show. So that's always going to be a form of home base for me," he told People ahead of its premiere. "And I'll always answer their call."

In season 18, Kate Walsh returned to Seattle as Dr. Addison Montgomery briefly to work on a groundbreaking surgery, and she's back again in season 19 — this time, in a recurring role throughout the season, Variety reported.

Shum joins the cast as Daniel "Blue" Kwan, one of several new surgical residents arriving at Grey Sloan. His official character bio, as reported by Deadline, describes him as "sharp-witted, impatient, and brilliant. He is generous by nature but competitive to a fault, naturally gifted, and used to winning at everything. A family crisis interfered with his career plans, and now he's got a lot to prove."

Before joining the "Grey's" family, Shum's small-screen roles included talented dancer Mike Chang on "Glee" and warlock Magnus Bane on "Shadowhunters." He also plays Charlie Wu in the "Crazy Rich Asians" film series and is set to co-lead a spinoff movie with costar Gemma Chan.

Kane, best known for her role as Mary, Queen of Scots, on "Reign," joins the cast as Jules Millin. Per her official character description (via TVLine), Jules "was raised by drug-addled artist/hippies and somehow emerged as the only real grown-up in the family. Because she always had to take care of herself and her parents, Jules can be a little bossy — but her heart is always in the right place. She's not afraid to break the rules to save a life, and sometimes it gets her in trouble." According to a first-look sneak peek previously posted on the official "Grey's Anatomy" Twitter account, Jules also has a previous connection with Atticus "Link" Lincoln.

Aside from her starring role in "Reign," Kane also played "wicked stepsister" Ivy on "Once Upon a Time," and more recently played Rebecca Bowen on "SEAL Team."

Terho plays Lucas Adams, another face in the new class of first-year surgical residents. His character description, per Deadline, states that he's "the charming black sheep of his family. Likable to a fault, he has a great mind but doesn't have the grades to match. He's determined to prove himself as a surgeon, just like many in his family that have come before him, but he will have to stop relying on his people skills and put in the work."

Terho already has one connection to "Grey's Anatomy": he costarred with Jake Borelli (aka Levi Schmitt) in the 2020 rom-com "The Thing About Harry."

Floyd is also part of the new "class" of residents, playing Simone Griffin. Deadline notes that her character's backstory is especially intriguing: "A funny, whip-smart, high achiever with a complicated family dynamic. She grew up in Seattle, but never wanted to work at Grey Sloan because of a painful personal history with the hospital."

Floyd is already part of the Shondaland family, having played "Neff" (a fictionalized version of Neffatari Davis, a concierge at NYC hotel 11 Howard) in "Inventing Anna." She also appeared on "The Bold Type" as Tia Clayton.

Francis, most recently seen as Alicia on "The Sex Lives of College Girls," makes up the quintet of new surgical residents at the start of the season. She plays Mika Yasuda, who is described by TVLine as "a middle child with eight siblings [who] is used to "being overlooked and underestimated — and uses it to her advantage. She's dealing with overwhelming student loans from med school, but she's scrappy and confident that she can make it in the program and rise to the top."

You might also recognize Francis from playing idealistic teenager Lily in Netflix's holiday comedy series "Dash & Lily."