The Fifteenth Doctor is an incarnation of the Doctor, the protagonist of the British science fiction television series Doctor Who. He is portrayed by Rwandan-Scottish actor Ncuti Gatwa in two series and two specials. As with previous incarnations of the Doctor, the character has also appeared in Doctor Who spin-offs, both during and after the character's televised appearances.
Within the series' narrative, the Doctor is a millennia-old alien Time Lord from the planet Gallifrey, with somewhat unknown origins, who travels in time and space in their TARDIS, frequently with companions. Usually, at the end of each incarnation's life, the Doctor regenerates; as a result, their physical appearance and personality changes. However, the Fifteenth Doctor emerged unconventionally, via "bi-generation", in which he split from his predecessor, the Fourteenth Doctor's body, rather than replacing him, allowing both incarnations to co-exist. In contrast to his predecessors, Gatwa portrays a Doctor who is attempting to let go of much of his recent emotional trauma, with a more emotionally balanced, liberated, fun-loving, and affectionate outward persona.