Doctor Who is well known for casting familiar faces in new roles (just look at the 12th Doctor), so you may not be surprised to learn that Bill Potts’ on-screen foster mum has been in the show before, albeit in a different space and time and in a rather different guise...

Who plays Bill’s foster mum?

Bill’s foster mum is played by actress Jennifer Hennessy. And her character's name is Moira, according to the BBC.

Where have we seen her in Doctor Who before?

Cast your mind back to David Tennant’s days at the Tenth Doctor and you might remember an episode called Gridlock. The third instalment in series three saw Ten coming face to face with a rather catty Ardal O’Hanlon on New Earth.

The feline faced Thomas Kincade Brannigan welcomed the Doctor into his car, which he shared with his human wife Valerie.

And Valerie just so happens to have been played by an actress called Jennifer Hennessy  the very same Jennifer Hennessy who's joined the cast of series 10.

Where else have we seen actress Jennifer Hennessy?

Aside from Doctor Who? Well, she played Jude in The Office, a man-hating shop-assistant named Julie in Two Pints of Lager and a Packet of Crisps, and even appeared as a vet in Pulling.

More recently you may have spotted her playing Emily Cratchit in BBC1’s Dickensian. 

Doctor Who continues on BBC1 on Saturdays