Samuel Anderson, known for Emmerdale, will star as Danny Pink, a recurring character who will travel with The Doctor and Clara on their travels, and is a teacher at the school where Clara works.
Steven Moffat, lead writer and executive producer, added: ‘For the fourth time in Doctor Who history, Coal Hill School is coming to the aid of the TARDIS. In 1963 teachers Ian Chesterton and Barbara Wright accompanied the First Doctor. These days it’s the turn of Jenna Coleman as Clara Oswald. And very soon now, Sam Anderson as Danny Pink will be entering the world of the Doctor. But how and why? Answers are coming later this year in Peter Capaldi’s first series of Doctor Who!’
Keeley Hawes, known for Ashes to Ashes dame and currently Line of Duty, will star as Ms Delphox, a villianous banker who will appear in Episode 5, written by Steve Thompson (A Journey to the Centre of the TARDIS), and who has a dark secret.
Steven Moffat commented on the announcement, "Anyone watching the amazing Line Of Duty will know that Keeley Hawes is having one hell of year, and now it's about to get even better as she achieves the greatest villainy yet attempted on Doctor Who: she plays a banker."
Keeley spoke about the role also, "I am delighted to join Doctor Who and to be working with this incredible team. Ms Delphox is a great character and someone I've had a lot of fun playing."
Series 8 is set to air in August.