The Game of Thrones star first entered the Who-niverse in 2006, when she appeared in two episodes of spin-off series Torchwood.
On Wednesday (24 May), it was announced that Varma, 49, would be appearing opposite Ncuti Gatwa’s incoming Doctor as a mysterious new character called the Duchess.
The actor, who has recently appeared in Netflix’s erotic thriller Obsession, said: “I’m thrilled to be in Doctor Who and particularly excited to be crossing cosmic paths with Ncuti, as the Doctor, and look forward to creating interplanetary mischief with him.”
Series showrunner Russel T Davies, meanwhile, described her character as “spectacular”, adding: “A whole new audience will be hiding behind the settee when the Duchess unleashes her terror.”
Varma joins an already star-studded cast appearing opposite Gatwa’s 15th Doctor and his companion Ruby Sunday (Millie Gibson) in the show’s next full series, which will begin over the Christmas period this year.
Mindhunter star Jonathan Groff and RuPaul’s Drag Race winner Jinkx Monsoon will also appear in the new series, with the casting of the two American musical theatre stars leading fans to speculate a musical Doctor Who episode could be on its way.
Before Gatwa takes over as the Doctor, however, the show will be helmed by returning Time Lord David Tennant, who is back for three special episodes in November to mark the show’s 60th anniversary.
Tennant will be joined by Catherine Tate as his much-loved former companion Donna Noble, while Heartstopper actor Yasmin Finney plays a character called Rose.