Soap and quiz show host Bradley Walsh will join Mandip Gill and Tosin Cole as Doctor Who's companions for the next series of the cult sci-fi show.
The trio will star alongside Jodie Whittaker who is set to become the thirteenth – and first female – Doctor Who when the show returns in autumn 2018.
The Broadchurch and Trust Me star Whittaker will take over in the Tardis from Peter Capaldi when the Time Lord regenerates as a woman for the first time after the Christmas special.
Walsh was widely tipped to be the Doctor's new assistant, although further details of his role are yet to emerge.
A fan of the show for 50 years, Walsh told the BBC: "I remember watching William Hartnell as the first Doctor. Black and white made it very scary for a youngster like myself.
"I was petrified, but even though I'd watch most of it from behind the sofa through my fingers, I became a fan...
"Am I thrilled to be part of this whole groundbreaking new dawn for the Doctor? Oh yes!"
Gill, who has appeared in Hollyoaks and Casualty, said she was "over the moon" to be appearing in the hit programme, while Cole, who has had roles in Star Wars and EastEnders, said he was excited to be "jumping in to this Doctor Who universe".