Carey Mulligan
OK, here’s one that hardcore Whovians will know about, but casual viewers may have forgotten entirely. Whatever your Doctor Who credentials, you’ll probably remember 2007’s “Blink,” the episode that introduced the terrifying Weeping Angels for the first time. It’s also known for being a rare “Doctor-lite” episode, as David Tennant’s Time Lord hardly features.
Instead, the protagonist of the episode is Sally Sparrow, as played by future Hollywood star Carey Mulligan. At this point in her career, the actress had appeared in movies like 2003’s Pride & Prejudice but she was two years away from her big break in Tinseltown – 2009’s An Education, for which she earned herself an Academy Award nomination.
Because the episode and the character of Sally proved such a success, showrunner Steven Moffat later revealed that the production team asked if she wished to stay on as a full-time companion. However, the rising star said no. I guess Doctor Who‘s loss is Hollywood’s gain.
David Harewood
Actor David Harewood has been a familiar face on British TV for a while but he’s managed to carve himself out a successful career across the Atlantic this decade, too, as fans may know him from his role as CIA agent David Estes in the first couple of seasons of Homeland and for currently playing Martian Manhunter on Supergirl.
Jump back to Christmas 2009, though, and Harewood made a guest appearance in Doctor Who – and it happened to be in one of the show’s most significant stories. Harewood showed up in David Tennant’s two-part swansong “The End of Time.” He played minor antagonist Joshua Naismith, a greedy billionaire who sought to use the Master’s genius in order to get a powerful device called the Immortality Gate up and running. Of course, the Master tricked him and used the device for his own ends.
In more recent years, Harewood has been linked to the role of the Doctor himself. When asked about who he thought the Thirteenth Doctor should be last year, he correctly guessed that the part would go to a black person or a woman (it went to Jodie Whittaker).