The Sixth Doctor is an incarnation of the Doctor, the protagonist of the British science fiction television series Doctor Who. He is portrayed by Colin Baker. Within the series' narrative, the Doctor is a centuries-old alien Time Lord from the planet Gallifrey who travels in time and space in the TARDIS, frequently with companions. At the end of life, the Doctor regenerates; as a result, the physical appearance and personality of the Doctor changes. Baker portrays the sixth such incarnation: conceived by producer John Nathan-Turner and Baker to be an arrogant and abrasive character. The Sixth is flamboyantly dressed in brightly coloured, mismatched clothes with a patronising personality intentionally written and portrayed to set him apart from all his previous incarnations.
Preceded in regeneration by the Fifth Doctor (Peter Davison), he is followed by the Seventh Doctor (Sylvester McCoy). The Sixth Doctor appeared in two seasons, although his first regular appearance was in The Twin Dilemma (1984), the final story of season 21. The Sixth appeared with only two companions on-screen, most notably the American college student Peri Brown (Nicola Bryant), who had travelled with his previous incarnation, before being briefly joined by Mel Bush (Bonnie Langford), a computer technician from his future.
Prior to its hiatus, season 23 was well into preproduction, with episodes under active development before BBC1 executive Michael Grade forcibly paused all production on Doctor Who. Once it was allowed to return, the planned production for season 23 was dropped in favour of the 14-episode story arc The Trial of a Time Lord. Unsatisfied with Baker's performance, Grade demanded Nathan-Turner terminate him from the role if Doctor Who was to be renewed for further seasons, despite Baker having signed up for four years. Baker, displeased by the treatment he received from the production during his tenure, refused to return to film his regeneration at the beginning of Time and the Rani (1987), offering instead to return for one last season where he would regenerate at the end, but receiving no further response after his counter-offer.
The Sixth Doctor's time on television received frequent criticism for its violence, darker tone compared to prior seasons of the show, and antagonistic relationship between the Doctor and companion Peri. Since the end of the Sixth Doctor's run, novels and audio plays have featured the character in further adventures, most prominently in those commissioned by Big Finish Productions; they have also been visually referenced several times in the revived 2000s production of the show. Baker eventually returned to play the role in the show 36 years after he had been fired to film a cameo as the Sixth Doctor in "The Power of the Doctor" (2022), where he appeared among multiple other past incarnations as figments within the consciousness of the Thirteenth Doctor (Jodie Whittaker).
Biography The Sixth Doctor (Colin Baker) was first seen briefly at the end of The Caves of Androzani (1984), where the Fifth Doctor (Peter Davison), having resisted regeneration throughout the latter half of the story, finally succumbs to his injuries and transforms into his latest incarnation.
Due to the circumstances of his prior iteration's death, the Sixth Doctor suffers from post-regeneration trauma in his debut The Twin Dilemma (1984), where he acts out erratically, seen in his strangulation of companion Peri Brown (Nicola Bryant), whom he accuses of being an "alien spy". Unaware of what he had done, but consumed with guilt as he witnesses the newfound terror felt towards him by Peri, the Doctor vows to "become a hermit" on the asteroid of Titan III, only to meet the lone survivor of a crashed ship and a mysterious dome on the asteroid's surface when they arrive. The Doctor and Peri go on to uncover and stop a conspiracy by a member of an alien species known as the Gastropods to hypnotise a pair of super-intelligent adolescents, whom they had planned to use to advance their nefarious goals; at the end of the story, the Doctor reassures Peri that, through the course of their debut adventure, he had since fully recovered from his earlier bout of madness, confidently insisting "I am the Doctor – whether you like it…or not!"
He went on to encounter many old foes including the Master (Anthony Ainley), Davros (Terry Molloy) and the Daleks, Cybermen, and the Sontarans, and shared an adventure with his own second incarnation (Patrick Troughton) in The Two Doctors (1985). The Sixth would face new enemies too, such as a renegade female Time Lord scientist, the Rani (Kate O'Mara), and Sil (Nabil Shaban), a repulsively greedy slug creature.
The Sixth Doctor would be subject to a trial arranged by the High Council of the Time Lords, beginning in The Mysterious Planet (1986). Under the prosecution of the Valeyard (Michael Jayston), the Doctor was accused of violating the Time Lord decree of non-inference, although more charges were added throughout The Trial of a Time Lord storyline. An adventure the Sixth and Peri had on the devastated planet Ravolox, which they discovered to actually be Earth, moved across space by unknown forces that resulted in devastating consequences, was shown as evidence. A separate adventure in Mindwarp (1986) was shown as further evidence, when the TARDIS landed on Thoros Beta and they reunited with the villainous Sil. What actually occurred here is left intentionally unclear, but initial accounts suggested that Peri was killed after being cruelly used as a test subject in brain transplant experiments, which the Doctor was stopped from preventing after having been pulled out of time by the Time Lords to face trial. Although as later revealed, the Valeyard had been tampering with evidence shown during the trial, specifically the recordings of the Doctor's travels; in reality, Peri had survived the events of the story, and went on to marry an alien warrior king met during the same period.
In reality, the trial was a cover-up organised by the High Council, sparked in reaction to an alien race from the Andromeda Galaxy stealing Time Lord secrets and hiding them on Earth; in an effort to dispose of the evidence, the Time Lords renamed Earth to Ravolox, moved it through space, and scorched the surface in a massive fireball, which the Doctor unknowingly uncovered much to his outrage. As the trial continued, the Valeyard would also be unmasked as an alternate, evil incarnation of the Doctor, who was an amalgamation of his darkest traits extracted between the Doctor's twelfth and final incarnations. The trial tangled the Doctor's timeline slightly, as he left in the company of future companion Mel Bush (Bonnie Langford), a fitness enthusiast from Pease Pottage, whom he technically had not met yet.
When the TARDIS is attacked by the Rani at the beginning of Time and the Rani (1987), the Sixth Doctor was somehow injured and regenerated into the Seventh Doctor (Sylvester McCoy); the exact cause of the regeneration, however, is not given on-screen.
Other appearances The Sixth Doctor starred in A Fix with Sontarans (1985), a segment of the children's television programme Jim'll Fix It, featuring the return of former companion Tegan Jovanka (Janet Fielding) and attacking Sontarans. His image has appeared among other incarnations in several revival series episodes, often in montages, beginning with "The Next Doctor" (2008). He was briefly portrayed via a stunt double for "The Name of the Doctor" (2013) and appears in "The Day of the Doctor" (2013) using archived footage. The Sixth returned in "The Power of the Doctor" (2022), marking 36 years since he last appeared on television, as a "vestige of [the Doctor's] consciousness", alongside previous Doctors, now all visibly aged as part of the "Guardians of the Edge" who are figments within the mind of the Thirteenth Doctor (Jodie Whittaker).
For the third episode of the spin-off series Tales of the TARDIS in 2023, the Sixth Doctor reunited with a returning Peri, now a warrior queen. Sixth appears as an older, bearded version, now sporting a pink three-piece suit with rainbow-coloured socks and a dog badge in place of his usual cat badge. The pair recount the events of Vengeance on Varos (1985) before setting off for further adventures.
Comics
The Sixth Doctor has featured in a number of comic stories published in Doctor Who Magazine, which ran concurrently with the television series during the 1980s. These comic stories featured the Sixth and Peri in new adventures, but would also introduce a new companion for him named Frobisher, a "self-styled, street-smart detective" and shapeshifting alien who often took the form of a penguin. Marvel UK went on to publish a comic featuring the Sixth Doctor and Frobisher written by Baker himself, titled The Age of Chaos, which centred on the two traveling to the planet Krontep "on a quest to track down Peri's grandchildren".
Novels
Multiple scrapped episodes that were a part of the original plan for season 23 of Doctor Who prior to the show's 18-month hiatus went on to be developed into novels (and later audio play recreations) as part of the Target Missing Episodes line beginning in 1994, which included The Nightmare Fair by Graham Williams, The Ultimate Evil by Wally K. Daly, and Mission to Magnus by Philip Martin.
The Sixth Doctor appeared briefly in the Seventh Doctor-centric Virgin New Adventures series, specifically in the novel Head Games by Steve Lyons, where he materialised as a manifestation of his own persona that goes on to attack the Seventh Doctor, accusing him of having gone down a darker path from his own. The Sixth featured more prominently in the Virgin Missing Adventures series of books, appearing in novels such as State of Change by Christopher Bulis, Time of Your Life and Killing Ground, both by Lyons, and Millennial Rites by Craig Hinton, which involved dimensional instabilities that led to the Sixth Doctor briefly transforming into the Valeyard. Similarly, the Sixth also headlined novels from the Past Doctor Adventures line, such as Business Unusual by Gary Russell, which acted as the companion introduction for Mel, unseen in the Doctor's original television tenure, Players by Terrance Dicks, which served as a sequel to The War Games (1969) and featured a returning Second Doctor, and Spiral Scratch, one of many interpretations behind the circumstances surrounding the Sixth Doctor's regeneration. He would cameo in the Eighth Doctor Adventures line, where he, among several other past incarnations, met the Eighth Doctor in The Eight Doctors.
Video games
The Sixth Doctor featured as the main protagonist in 1985's Doctor Who and the Mines of Terror where he works to stop the Master from "setting himself up as the Devil at the beginning of time" so he can be immortal. The Sixth appeared alongside the first seven incarnations of the Doctor in 1998's Destiny of the Doctors, where he and the others have been captured by the Master (played by a returning Ainley) and must be rescued by the player character. The Sixth was also featured in 2015's Lego Dimensions as one of the incarnations of the Doctor the player could unlock and play as.
Audio dramas