Meet the New Characters Headed to Mayfair in Bridgerton Season 4 (Including a Harry Potter Alum!)

Yerin Ha as Sophie Baek

Ha plays leading lady Sophie, a maid who meets Benedict while disguised as the Lady in Silver at the first ball of the season (a masquerade!), ultimately setting him on a mission to find the mystery woman.

During an October 2024 interview with Shondaland, Ha revealed that she was having breakfast with her mom at a cafe in Korea when she found out she got the lead season 4 role.

“She came out crying, and then after the phone call, she was like, ‘We gotta go home. I think I have indigestion,’ and so we left,” she said. “It was really beautiful to kind of, I guess share that moment with her.”

Prior to her role in Bridgerton, the Australian actress appeared in several episodes of HBO Max’s Dune: Prophecy, Paramount+’s Halo and the Australian miniseries Stan.

Katie Leung as Lady Araminta Gun

Katie Leung joins the cast as Lady Araminta Gun, a twice-married, twice-widowed mother of two, whose daughters are both on the marriage mart this season. Otherwise known as Lady Penwood, she is also Sophie’s stepmother.

Ahead of the season 4 premiere, the actress shared a photo of her character on Instagram, captioned, “This mama ain’t messing about.” Quinn commented, “You. Are. Epic.”

Leung is best known for portraying Cho Chang in several Harry Potter films, as well as her role in the animated series Arcane.

Michelle Mao as Rosamund Li

Michelle Mao was courted to play Rosamund Li, Araminta’s eldest daughter (and in many ways, mini-me) who is eager to marry this season.

Ahead of the premiere, the actress spoke to IMAGINE Magazine about landing the role, saying, “Never in my wildest dreams did I even dare to imagine that I could be on a show as loved and as grand as Bridgerton.”

Before heading to Mayfair, Mao appeared in 2025’s A Big Bold Beautiful Journey and will act in 2026’s Zi, alongside Haley Lu Richardson.

Isabella Wei as Posy Li

Another new season 4 addition is Posy Li, Araminta’s younger daughter, played by Isabella Wei. She is the kinder, chattier and quirkier of the two Li girls, though she is often cast in her sister’s shadow by her mother.

During a January 2026 conversation with Numero Netherlands, Wei revealed that she was in New York with her father when she found out she had been cast.

“I ran up to his hotel room early in the morning and frantically pounded on his door, then we FaceTimed the family together and squealed and screamed,” she said, adding that she was “so ecstatic.”

Wei also spoke about bringing Posy to life, saying that her “enthusiasm and openness are what make her unapologetically herself.”

She added, “I feel so privileged to help craft those moments of joy that come from her.”

Wei previously appeared in several episodes of Netflix’s 1899 and Black Doves, as well as 2024’s The Crow and 2025’s High Wire.

Fiona Marr as Irma Gibbons

Fiona Marr makes her Bridgerton debut as Irma Gibbons, a cook who grows close to Sophie while working together for the Penwoods.

Marr made guest appearances in Apple TV’s Silo and Paramount+’s The Gold, and appeared in 2025’s My Fault: London.

David Moorst as Alfie

David Moorst portrays Alfie, the witty footman who works alongside Irma and Sophie at the Penwood House — and who has a role in pushing Sophie to attend the masquerade.

Moorst has appeared in several productions on London’s West End, including To Kill a Mockingbird and A Midsummer Night’s Dream. He also made a guest appearance in Killing Eve.

Susan Brown as Mrs. Crabtree

Susan Brown portrays Mrs. Crabtree, the nurturing housekeeper of Benedict’s country home, who also plays a key role in his and Sophie’s love story.

The actress appeared as a guest star in HBO’s Game of Thrones, and had roles in 2013’s Belle and 2011’s The Iron Lady.

Billy Boyle as Mr. Crabtree

Billy Boyle joins the cast as Mr. Crabtree, the other half of the married duo taking care of Benedict’s country home, “My Cottage.”

The Irish actor has worked in the industry for several decades, having appeared in film, television and theater. He is best known for having held the leading role in over 15 hit shows on the West End.

Gracie McGonigal as Hazel

Gracie McGonigal steps into the working class under the ton as Hazel, a maid who becomes a close friend of Sophie.

Prior to joining the cast, McGonigal got her start as a London-based musical theater actress who has starred in several productions, including Into the Woods and Fangirls.