Whittaker is the first female to portray an incarnation of the iconic time-traveler.
The the British sci-fi series' 10-episode Season 11 -- which will feature a 1-hour premiere followed by 50-minute episodes -- is to debut on the BBC in autumn 2018.
"The new Doctor is going to need new friends. We're thrilled to welcome Mandip, Tosin and Bradley to the Doctor Who family. They're three of Britain's brightest talents and we can't wait to see them dive into brand new adventures with Jodie's Doctor. Alongside them, we're delighted that[previous guest star] Sharon D. Clarke is also joining the show," head writer and executive producer Chris Chibnall said in a statement Sunday.
"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," Walsh added.
"I then queued up for ages to get into the Carlton picture house in Watford to watch the great Peter Cushing appear as the Doctor in a full length feature-film made in glorious color. Am I thrilled to be part of this whole ground-breaking new dawn for the Doctor? Oh, yes!"
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