The popular comedian, actor and broadcaster will join Peter Capaldi and Jenna Coleman in the season finale.
Speaking about the role, Bhaskar said: “I’m thrilled to have made a small contribution to and now be part of the Doctor Who universe. Another dream box ticked!”
Steven Moffat, lead writer and Executive Producer, says: “I’m completely thrilled that Sanjeev Bhaskar is coming to the aid of the Doctor. The danger is never deadlier than in a finale episode, and the Time Lord is going to need all the help he can get!”
The series returns to BBC One on 23 August and will also feature appearances by Michelle Gomez, Frank Skinner, Ben Miller, Tom Riley, Keeley Hawes and Hermione Norris.