Barbara Wright is a fictional character in the British science fiction television series Doctor Who and a companion of the First Doctor. She was one of the programme's first regulars and appeared in the bulk of its first two seasons from 1963 to 1965, played by Jacqueline Hill. Prior to Hill being cast the part had originally been offered to actress Penelope Lee, who turned the role down. Barbara appeared in 16 stories. In the film version of one of the serials, Dr. Who and the Daleks (1965), Barbara was played by actress Jennie Linden, but with a very different personality and backstory, which includes her being a granddaughter of "Dr Who".

The First Doctor is the original incarnation of the Doctor, the protagonist of the British science fiction television series Doctor Who. He was portrayed by actor William Hartnell in the first three series from 1963 to 1966 and the tenth anniversary story The Three Doctors from 1972 to 1973. The character would occasionally appear in the series after Hartnell's death, most prominently as portrayed by Richard Hurndall in the 1983 multi-doctor special The Five Doctors, and as portrayed by David Bradley in the 2017 Twelfth Doctor episodes "The Doctor Falls" and "Twice Upon a Time" and in the 2022 Thirteenth Doctor episode "The Power of the Doctor", the latter previously having portrayed Hartnell himself in the 2013 biopic An Adventure in Space and Time.