The History Boys actor Samuel Anderson is to join the cast of Doctor Who as a companion to Clara Oswald, played by Jenna Coleman.
Anderson will play Danny Pink, a teacher at Coal Hill School where Oswald also teaches.
The eighth series will also introduce Peter Capaldi as the latest Doctor.
"I was so excited to join Doctor Who, I wanted to jump and click my heels but I was scared I might not come down before filming started," Anderson said.
"It's a quintessential part of British culture and I can't believe I'm part of it. It's an honour to be able to work alongside Peter Capaldi and Jenna Coleman and I can't wait to show people how my character becomes involved with such a fantastic duo."
In 1963, teachers Ian Chesterton and Barbara Wright accompanied the first Doctor in the classic series, so events have now come full circle.
Filming has recently begun on the fourth and fifth episodes of the eighth series of the Doctor Who reboot, which kicked off in 2005 with Christopher Eccleston as the Doctor.
Anderson has also starred in Gavin & Stacey and soap opera Emmerdale - where he played police officer Jason Kirk from 2007 to 2009.
He played Crowther in Alan Bennett's hit play The History Boys at the National Theatre and reprised the role in the film version.