Meet the 13th Doctor's new friends! Yasmin (Mandip Gill), Ryan (Tosin Cole), and Graham (Bradley Walsh) #DoctorWho pic.twitter.com/6l9iVkvu0d

— Doctor Who (@bbcdoctorwho) October 22, 2017

Radio Times reports “Doctor Who: Bradley Walsh, Tosin Cole, Mandip Gill and Sharon D Clarke join Jodie Whittaker as regular cast members”.

• Bradley Walsh, long touted as the man who will accompany the new Doctor on her travels, will be joining the cast of Doctor Who in the role of Graham.
• Tosin Cole plays a new character called Ryan. Tosin also had a brief appearance in the 2015 Star Wars: The Force Awakens as the X-Wing pilot Lt. Bastian.
• Mandip Gill, who played Hollyoaks’ Phoebe Jackson among other roles in other shows, is playing a character called Yasmin
• Actress and singer Sharon D Clarke is to become another regular in what the BBC describes as a “returning role”. However it has not yet been made clear who the character she will play is – or whether she will take over the part of one of the Doctor’s adversaries or friends.

They’ll be on hand when Doctor Who resumes with a 10-part series in Autumn 2018.

Sharon D Clarke