John Bishop joins Doctor Who for next series Friday 1st January 2021, 10:05pm John Bishop is to join the cast of Doctor Who The series is currently filming and will begin airing later this year on BBC One The BBC has announced that John Bishop will star in the next series of Doctor Who. He will effectively replace Bradley Walsh in the long-running sci-fi series when it returns later in 2021. Filming began in November. It will be the programme's thirteenth series since its 2005 revival. Bishop plays new companion Dan, joining current Doctor Jodie Whittaker and female companion Yaz, played by Mandip Gill.