The Thirteenth Doctor is an incarnation of the Doctor, the protagonist of the BBC's science fiction television series Doctor Who. She is played by Jodie Whittaker, the first woman to portray the character, in three series, five specials and a cameo in the fifteenth series. As with previous incarnations of the Doctor, the character has also appeared in other Doctor Who spin-offs, both during and after the character's televised appearances.

Within the series's 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. At the end of life, the Doctor regenerates; as a result, the physical appearance and personality of the Doctor change. Whittaker's incarnation is a light-hearted adventurer with a passion for building things, placing a high value on friendships and striving for non-violent solutions. Preceded in regeneration by the Twelfth Doctor (Peter Capaldi), she is followed by the Fourteenth Doctor (David Tennant).

This incarnation's first companions were a trio consisting of retired bus driver Graham O'Brien (Bradley Walsh), his dyspraxic step-grandson and part-time warehouse worker Ryan Sinclair (Tosin Cole), and probationary police officer Yasmin "Yaz" Khan (Mandip Gill), all of whom she met shortly after her regeneration. After Graham and Ryan leave, the Doctor and Yaz are joined by food bank volunteer Dan Lewis (John Bishop). She also had one-episode reunions with former companions Captain Jack Harkness (John Barrowman), Tegan Jovanka (Janet Fielding), and Ace (Sophie Aldred).

Casting In January 2016, Steven Moffat announced that he would leave the show after the tenth series; he was set to be replaced by new showrunner, Chris Chibnall. Peter Capaldi confirmed a year later that the tenth series would be his last as well. Following this news, several media reports and bookmakers had speculated as to who would replace Capaldi as the Thirteenth Doctor. Bookmakers' favourites included Ben Whishaw, Phoebe Waller-Bridge, Kris Marshall, and Tilda Swinton.

Casting a woman The concept of a female Doctor was first mentioned in 1981, when Tom Baker suggested his successor might be female, after announcing the end of his tenure as the Fourth Doctor. Producer, John Nathan-Turner, later discussed the possibility of casting a woman as the Sixth Doctor to replace the departing Peter Davison's Fifth Doctor, claiming it was feasible, but not something he was considering at the moment. In October 1986, during the transmission of Colin Baker's final season as the Sixth Doctor, series creator, Sydney Newman, wrote to BBC Controller, Michael Grade, with a suggestion that "at a later stage, Doctor Who should be metamorphosed into a woman". Dawn French, Joanna Lumley, and Frances de la Tour, were suggested by Newman in 1986 for the role, but were dismissed by the BBC. Lumley later appeared as a satirical version of the Thirteenth Doctor in the 1999 Comic Relief special, The Curse of Fatal Death. Arabella Weir also played an alternative Third Doctor in the Doctor Who Unbound Big Finish episode, Exile. Neither portrayal is typically considered to be within the show's main continuity. Producer, Jane Tranter, also considered casting Judi Dench as the Ninth Doctor.

The concept of Time Lords changing sex upon regeneration was seeded throughout Moffat's tenure as showrunner. Just after regenerating, the Eleventh Doctor exclaims "I'm a girl?" In the 2011 episode, "The Doctor's Wife", the Doctor recalls a Time Lord acquaintance known as the Corsair, who had at least two female incarnations. In the 2013 short, "The Night of the Doctor", the Sisterhood of Karn offer a dying Eighth Doctor (Paul McGann) control over his inevitable regeneration, with "man or woman" being touted as possibilities. The first on-screen cross-gender regeneration was shown in the 2015 episode, "Hell Bent", in which a white male Gallifreyan general (Ken Bones) regenerates into a black woman (T'Nia Miller), who states that her previous incarnation was the only time she had been a man.

The most notable Time Lord to have appeared in both male and female forms prior to Whittaker's casting is the Doctor's nemesis, the Master, portrayed from 2014 to 2017 by Scottish actress, Michelle Gomez. This version of the character was known as Missy, short for "Mistress". The tenth series finale, "World Enough and Time" / "The Doctor Falls", addresses cross-gender regeneration several times; the Doctor tells his companion Bill Potts (Pearl Mackie) that Missy was "his first man-crush", and adds that he is only "fairly sure" he himself was male at the time, although the remark may have been flippant.

Two years prior to the announcement of Whittaker's casting, fans and scholars discussed the possibility of a female Doctor and analysed the benefits of such a regeneration.

Casting Whittaker

When referring to whether the new Doctor would be a woman, incoming Doctor Who showrunner Chris Chibnall originally was quoted in February 2017, as saying, "Nothing is ruled out but I don't want the casting to be a gimmick and that's all I can say". On 14 July 2017, the BBC announced that the portrayer of the Thirteenth Doctor would be revealed after the 2017 Wimbledon Championships men's finals on 16 July 2017. Whittaker was introduced as the Thirteenth Doctor on 16 July and subsequently made her debut in the 2017 Christmas special "Twice Upon a Time" and starring in the eleventh series. On Whittaker's casting, Chibnall said, "I always knew I wanted the Thirteenth Doctor to be a woman and we're thrilled to have secured our number one choice. Her audition for The Doctor simply blew us all away." Later on in his statement, Chibnall called Whittaker "an in-demand, funny, inspiring, super-smart force of nature" and said that she "will bring loads of wit, strength and warmth to the role."

In an interview with Tenth Doctor actor and Broadchurch co-star David Tennant, Whittaker said she did not grow up watching Doctor Who and had decided against watching it to prepare for the role, saying: "I started to watch a bit during my audition process and I quickly decided that was not the way for me...It just made me panic...[Chibnall] said to me, 'you're not coming in and playing the Doctor, you're playing the truth of the scene and the Doctor will come out of that'... so, that's what I did."

In November 2018, BBC confirmed that the twelfth series, Whittaker's second series, began production in November 2018. The series premiere aired on 1 January 2020. Whittaker continued on in the role for the thirteenth series.

Whittaker and Chibnall stated they would exit the show following the thirteenth series and three specials, which aired through 2022. Chibnall said "Jodie and I made a 'three series and out' pact with each other at the start of this once-in-a-lifetime blast. So now our shift is done, and we're handing back the Tardis keys. Jodie's magnificent, iconic Doctor has exceeded all our high expectations." She was succeeded by Tennant as the Fourteenth Doctor.

Characterisation Interviewed by Radio Times, Chibnall described the Thirteenth Doctor as "absolutely the Doctor, but there's a new calibration, a new mixture of Doctorishness. The Thirteenth Doctor is incredibly lively, warm, funny, energetic, inclusive – she's the greatest friend you could wish to have as your guide around the universe." In the same article, Whittaker also added that her Doctor "speak[s] at a hundred miles an hour," while actress Mandip Gill who plays companion Yaz Khan, commented that Whittaker's Doctor "has a similar energy to Matt Smith's Doctor... Very high energy. Jodie has that about her Doctor."

Costume

In the clip in which the casting of Whittaker was announced, she wears a grey overcoat over a black hoodie. The first images of Whittaker's official costume as the Doctor were released to the media on 9 November 2017.

The Thirteenth Doctor's costume features blue high-waisted culottes with yellow braces, a navy blue t-shirt with a rainbow stripe across it, a lilac-blue trenchcoat with a hood, brown lace-up boots, blue socks and piercings on her left ear. Some fans noted that the outfit had similarities to earlier Doctors' costumes, with others comparing it to Robin Williams' costume in the American sitcom Mork & Mindy.

Whittaker stated that she worked with the show's costume designer Ray Holman (who had also worked before with Whittaker on Broadchurch) to come up with her outfit, inspired by a photograph that she had found online. The photograph had been published in a 1988 issue of Sassy showing a number of female models in men's clothing, with the specific photo of a woman in trousers, braces and a T-shirt, walking with a purpose. Whittaker said she "just love[d] the androgyny of it, without it being masculine", and that "felt intriguing and kind of open to interpretation and I really love that". Additional elements drew out from the photograph. Whittaker wanted a coat that flowed with her actions and gave her pockets but otherwise did not have any fasteners, and she wanted some colour within the outfit but without going too "cartoonish". Holman added violet to the inside of the coat's sleeves, a reference to the violet-and-green colours of the Suffragettes.

Appearances Television The Thirteenth Doctor makes her debut in the final scene of 2017 Christmas special "Twice Upon a Time". After regenerating, The Doctor falls out of the TARDIS and, in series premiere "The Woman Who Fell to Earth" (2018), lands in modern-day Sheffield, where she befriends retired bus driver Graham O'Brien (Bradley Walsh), his wife's grandson Ryan Sinclair (Tosin Cole), and police officer Yasmin "Yaz" Khan (Mandip Gill), with whom she successfully repels an alien hunter from the warlike Stenza race. The Doctor builds a device to return her to the TARDIS, but accidentally teleports her new friends with her; the group help retrieve the TARDIS on an alien world in "The Ghost Monument". After a trip to segregation-era Alabama in "Rosa", Graham, Ryan, and Yaz agree to being full-time companions in "Arachnids in the UK". Subsequent trips include visiting Yaz's grandmother in 1947; witnessing the partition of India in "Demons of the Punjab"; preventing a plan to kill millions galaxy-wide as part of a labour protest, in "Kerblam!"; and repelling an alien invasion alongside James VI and I in Jacobean Lancashire, in "The Witchfinders". In series finale "The Battle of Ranskoor Av Kolos", the Doctor is drawn into a second confrontation with the Stenza she faced in Sheffield. In the New Year's Day special "Resolution" (2019), her friends encounter a Dalek for the first time when it is awakened by archaeologists in Sheffield. The Dalek is defeated before it can signal a broader Dalek invasion of Earth.