Who was the first companion introduced in the Thirteenth Doctor's first episode?

Ryan Sinclair was the first companion introduced in the Thirteenth Doctor’s first episode, “The Woman Who Fell to Earth.” The episode, broadcast on 7 October 2018, was Jodie Whittaker’s first full appearance as the Thirteenth Doctor and introduced her new Sheffield-based companion group.

Ryan is first encountered while struggling to ride a bicycle in a wooded area, where he becomes involved in the Doctor’s investigation of a strange alien object. His dyspraxia is part of his characterisation, and the episode shows his frustration with cycling alongside his growing courage during the alien threat. Ryan is played by Tosin Cole.

The episode also introduces Yasmin Khan and Graham O’Brien, who later travel with the Doctor alongside Ryan. Bill Potts belongs to the Twelfth Doctor’s era, so she is not part of this new companion group. Ryan remained a regular companion through the Thirteenth Doctor’s era until “Revolution of the Daleks” in 2021.