Aliases of the Doctor

Throughout their travels in time and space, the Doctor took on and was called by a number of different aliases, titles and names. Some were fleeting. Others, like John Smith, were used by almost all of their incarnations. The Doctor told few people their real name. Instead, they asked others to call them simply, the Doctor.

The Doctor's real name

 * As the Time Lord's true name was not generally known, "the Doctor", or "Doctor Who", became an alias and the exact reason for the Doctor to hide their true name is a complete mystery.

One account implied that their given name was ceremoniously withdrawn and stricken by their Cousins as punishment for a disgrace they brought upon their House. (PROSE: Lungbarrow)

Even when put on trial by the Time Lords, they were only referred to as "the Doctor", (TV: The War Games) although the Valeyard, a culmination of the Doctor's darker side who prosecuted the second trial, acknowledged that this was an alias. (TV: The Mysterious Planet) When the Fifth Doctor was officially inducted as Lord President, he declared that it was "out of the question" for him to be introduced by his true name, stating that he would accept being introduced as "Lord President Doctor". (AUDIO: Time in Office) Even those who had known them in childhood addressed them only as "the Doctor", such as the Master, (TV: Death in Heaven) and the Rani. (COMIC: Weapons of Past Destruction)

According to one account, during their first incarnation, the Doctor adopted this name in dealing with human colonists on the planet Iwa at the same time that his granddaughter adopted the name "Susan". (PROSE: Frayed) Another account implied that the Doctor's title had been chosen as a Gallifreyan custom, (TV: The Sound of Drums) and that he had been using it before he left Gallifrey. (TV: The Name of the Doctor, World Enough and Time)

The Doctor's real name has been said to be difficult to pronounce, for humans at least, (AUDIO: Slipback) and certainly for adults, (TV: Twice Upon a Time) possessing thirty eight syllables. (PROSE: Sleepy) The First Doctor once told an interrogator he "wouldn't be able to pronounce the first syllable of [his name]." (PROSE: Salvation) His seventh incarnation likewise told one of his captors that he "doubt[ed] [they]'d be able to pronounce the name [he] was originally given." (PROSE: Illegal Alien) When asked about the Doctor's name, Peri Brown once said that the Doctor had told her she would find it unpronounceable. (AUDIO: Slipback) Moments before his regeneration, however, the Twelfth Doctor stated his belief that "children [could] hear [his name]", but only when "their hearts [were] in the right place, and the stars [were] too." (TV: Twice Upon a Time)

The Doctor kept their true name hidden despite numerous "mind-probe" attempts and the effect of a truth field. (TV: The Girl in the Fireplace, The Time of the Doctor) The Carrionite Lilith, unable to discover the Tenth Doctor's true name even with the "witchcraft" used by her kind, remarked that "there [was] no name," and that the Doctor was hiding it in despair. (TV: The Shakespeare Code) The psychically-gifted Evelina, who attempted to foretell the Doctor's future, remarked that his "true name" was "hidden" from her. (TV: The Fires of Pompeii)

Significance
The Eleventh Doctor told Clara Oswald that his real name was not important since he specifically chose the title of "Doctor" to take its place, saying it was "like a promise [one made]." (TV: The Name of the Doctor) This promise was; ''"Never cruel or cowardly. Never give up, never give in."  (TV: The Day of the Doctor'') Even Clara considered "the Doctor" to be his true name and the only one that mattered. (TV: The Time of the Doctor) Despite their hatred of the War Doctor's actions, (TV: The Name of the Doctor) both the tenth and eleventh incarnations admitted "[he] was the Doctor more than [any of them]." (TV: The Day of the Doctor) When Clara was forced to take on his role for him, the Twelfth Doctor told her that "goodness has nothing to do with [being a Doctor]". (TV: Flatline)

The Doctor considered abandoning his name if he felt he had to do something highly immoral. (TV: The Beast Below, Face the Raven) The War Doctor rejected the name to fight in the Time War, (TV: The Night of the Doctor) but proudly called himself the Doctor once he was given the chance to end the conflict without killing the Time Lords. (TV: The Day of the Doctor) During his final day, the Twelfth Doctor stated being "the Doctor" was being kind, even if it meant pulling a self-sacrifice to bring others a small amount of extra time to live. (TV: The Doctor Falls) The Thirteenth Doctor said that a "bit of adrenaline, dash of outrage and a hint of panic" helped her to remember she was the Doctor. (TV: The Woman Who Fell to Earth)

knew of this and implied that the Doctor's title had been chosen because it meant "the man who makes people better", although he found the choice "sanctimonious" for someone who ended millions of lives and ruined many others. (TV: The Sound of Drums) River Song was aware of this contradiction in the Doctor's behaviour: she said that the Doctor was the first to have this title and that the rest of the universe later adopted it, usually to mean "healer" or "wise man". However, she added that, in some parts of the universe, such as in the Gamma Forests, it eventually came to mean "mighty warrior". (TV: A Good Man Goes to War)

According to Dorium Maldovar, the Silence had a particular interest in the Doctor's name. He explained that if the Doctor lived long enough, "on the fields of Trenzalore, at the fall of the Eleventh, [when] no creature could speak falsely or fail to answer", a question that must never be answered would be asked: "Doctor Who?". The Silence wanted to stop the Doctor from revealing his true name. (TV: The Wedding of River Song)

The Doctor was at a later time forced to go to Trenzalore to rescue his friends from the Great Intelligence, which sought to gain access to the Doctor's tomb. The tomb, which was a future version of his own dying TARDIS, would open only to the Doctor's real name. The Intelligence threatened to kill Clara Oswald and the Paternoster Gang if he did not speak his name and open the tomb; the situation was resolved when the data ghost of River Song was able to silently transmit his name to the TARDIS, thus opening the door for the Great Intelligence. (TV: The Name of the Doctor)

The Doctor's real name became important during the Siege of Trenzalore, as it was the signal chosen by the Time Lords to come back to the universe, broadcasting the question "Doctor Who?" through a crack in reality, simultaneously broadcasting a Truth Field so that they could be sure that it was truly the Doctor responding to them. Despite this, when the Doctor was facing death, Clara told the Time Lords through the Crack that the only name of his that mattered was "the Doctor" and everything he stood for under that name, prompting them to give the Doctor a new regeneration cycle at the cost of closing the crack. (TV: The Time of the Doctor)

After meeting his twelfth incarnation, the First Doctor was confronted by the mysterious Testimony Foundation, who claimed that the Doctor was the "Doctor of War". Although the First Doctor initially feared this interpretation of his future, after witnessing the Twelfth Doctor's efforts to save Captain Archibald Hamish Lethbridge-Stewart, he came to conclude that the "Doctor of War" was not a man who revelled in war, but a man who sought the moments of peace that existed amid open warfare, and who would always try to find another way to end war, and to find resolution, rather than resorting to bloodshed. (TV: Twice Upon a Time)

Ubiquity of the title
The Doctor did possess at least one doctorate. (TV: The Moonbase, The Armageddon Factor, The Mysterious Planet) They sometimes described themselves as a "doctor of many things" (TV: Four to Doomsday) or of "everything", (TV: Spearhead from Space, Utopia) as well as "a scientist, an engineer, builder of things". (TV: The Aztecs) However, their knowledge was limited to anything prior to the Rassilon Era. (TV: Utopia) The Eleventh Doctor claimed that one of his doctorates was in cheesemaking, (TV: The God Complex) but only the "stinky, blue kind". (PROSE: Shroud of Sorrow)

On several occasions, the Doctor claimed they were not a medical doctor. (TV: "The Forest of Fear", "Mighty Kublai Khan") Though by their second incarnation, he had studied medicine in the 19th century, (TV: The Moonbase) although Clara recalled the Doctor telling her that he graduated in the wrong century. (TV: Death in Heaven) The Eleventh Doctor described himself as a medical doctor. (TV: The God Complex) The seventh, eleventh and twelfth incarnations displayed some medical knowledge, being able to help with minor injuries (TV: Remembrance of the Daleks, The Vampires of Venice) and tell if a person was vitamin deficient. (TV: Thin Ice) The Ninth Doctor could also diagnose patients in a hospital ward, quickly deducing they all shared the injuries of a scar on the back of their hands, collapsed chest cavities, crushed rib cages and gas masks fused into the flesh on their faces, (TV: The Empty Child) and displayed extensive knowledge on nanogenes, such as their ability to repair organic matter and restore life as a mere "quirk of matter". (TV: The Doctor Dances) The Tenth Doctor in particular proved a proficient medic, performing life-saving surgery on Laszlo, sustaining him as a Human-Pig hybrid, able to live as long as a human again. (TV: Evolution of the Daleks)

When asked by Mabli if her doctorate was in medicine, the Thirteenth Doctor described herself as having a doctorate in "medicine, science, engineering, candyfloss, Lego, philosophy, music, problems, people, [and] hope." (TV: The Tsuranga Conundrum)

Individuals with knowledge of the Doctor's name
Susan Foreman knew the Doctor's real name, and wrote it on the wrappings of a hypercube she sent to him after she had settled down on Earth. (PROSE: Ghost of Christmas Past)

The Sixth Doctor told his dance instructor, Becky, his name. (PROSE: Teach Yourself Ballroom Dancing)

The Eighth Doctor's companion, Sam Jones, overheard his real name being said. She found it quite alien and virtually unpronounceable. (PROSE: Vanderdeken's Children)

When the Tenth Doctor first encountered her, River Song claimed to have known him at some point in his future, (TV: Silence in the Library) and, to prove her "credentials", she whispered his name in his ear, and apologised for having to do so. The Doctor was shocked at this, as "there [was] only one reason [he] would ever tell anyone [his] name, [and] only one time [he] could." (TV: Forest of the Dead) River indicated to Clara Oswald that she "made" the Doctor tell her his name and that "it took a lot of effort". (TV: The Name of the Doctor)

Near the end of his life, despite believing there was no one left in the universe who knew it, the Tenth Doctor encountered members of an unidentified pan-dimensional race that knew his real name. (AUDIO: The Last Voyage)

While separated from the Eleventh Doctor, Clara Oswald read his name in The History of the Time War. Though that timeline was aborted, leaving her with no memory of it, (TV: Journey to the Centre of the TARDIS) she later began to recall certain moments of the timeline, (TV: The Name of the Doctor) and claimed to know the Doctor's name when bluffing to the Cybermen about being the Doctor. (TV: Death in Heaven)

claimed to know the Doctor's real name from their time together on Gallifrey. She said it was "Doctor Who", and the Doctor had chosen it to be mysterious, but dropped the "Who" when he realised it was "too on-the-nose". The Twelfth Doctor said she was just teasing Bill Potts, but he refused to answer if it was truly his name. (TV: World Enough and Time)

John Smith
John Smith was an alias the Doctor frequently used on Earth and around humans when a "standard" name was needed, with the Eighth Doctor noting it was "the nom de guerre [he] seem[ed] to keep ending up with". (PROSE: Alien Bodies) It was often preceded by the title "Doctor", though not always — for example, when he was undercover as a teacher at a school or a patient in a hospital. (TV: School Reunion, Smith and Jones) As "John Smith" was considered a generic name in some Earth cultures, the Doctor's use of the alias was occasionally treated with scepticism. (TV: Midnight)

The First Doctor used a library card with the name Dr J. Smith while living at 76 Totter's Lane, (TV: The Vampires of Venice) as well as for identification when renting the junkyard. (PROSE: The Rag & Bone Man's Story) The inspiration for the alias was John Smith of John Smith and the Common Men, with which he was familiar through Susan. (PROSE: The Witch Hunters)

In their second incarnation, the name was independently used by his companion Jamie McCrimmon while the Doctor was being treated for a concussion, as he saw it being used as a brand name on a metal container. (TV: The Wheel in Space) The Doctor himself used the alias when being interrogated by a German soldier. (TV: The War Games) Likewise, Chang Lee chose to register the name for the Seventh Doctor while he was en route to get his bullet wounds healed. (TV: Doctor Who)

The Doctor adopted the name on a semi-regular basis during their third incarnation while exiled on Earth, when he served as unpaid scientific advisor to UNIT. (TV: Spearhead from Space, Inferno, The Time Warrior) The UNIT files referred to him as "Dr. J.S.". (AUDIO: Tales from the Vault)

The Doctor twice changed himself into a human who used the name John Smith. This occurred in their seventh incarnation, (PROSE: Human Nature) and in their tenth incarnation. (TV: Human Nature)

Often, the Doctor would use variations of the name, like the online handle "jsmith", jsmith8", (PROSE: Blue Box, Lonely) the French variation "Jean Forgeron", (COMIC: The Forgotten) or the German translation "Johann Schmidt". (PROSE: The Shadow in the Glass; AUDIO: Storm Warning)

The Thirteenth Doctor once made use of a variant, "Jane Smith", while hiding her true identity from Martha Jones. (COMIC: A Little Help from My Friends)

Doctor Who
The name "Doctor Who" was applied to the Doctor on several occasions. When the First Doctor was using the name "Doctor Caligari" and someone remarked, "Doctor who?" he replied, "Yes, quite right."; (TV: The Gunfighters) similarly, when Jimmy Forbes asked "Doctor who?", another incarnation of the Doctor replied "Yes, if you like." (AUDIO: Seven Keys to Doomsday) The TARDIS-Keeper on Gallifrey also knew the Doctor as "Who". (PROSE: Doctor Who and the Doomsday Weapon)

The computer WOTAN repeatedly referred to the First Doctor as "Doctor Who". (TV: The War Machines) Both Ian Chesterton and Vicki occasionally called the Doctor "Doctor Who", (PROSE: Doctor Who and the Zarbi) as did Argon, (PROSE: Terror on Tiro) Mitzog, (PROSE: The Cloud Exiles) and Phlege. (COMIC: Mission for Duh) The Doctor's grandson John (COMIC: The Klepton Parasites) had the last name "Who". (PROSE: Beware the Trods!)

The First Doctor used the username "Dr_who" when bidding on the TARDIS, which he lost to Buchanan in a bet, on RetroAuction.com in 2006. (PROSE: The Mother Road)

The Second Doctor briefly used the name "Doktor von Wer" (literally, "Doctor [of] Who") during his visit to Scotland on 16 April 1746, (TV: The Highlanders) and once signed a message as "Dr W." (TV: The Underwater Menace) The Zaons called him "Doctor Who". (PROSE: Daleks Invade Zaos)

Bessie's license plate during the Third Doctor's time at UNIT read WHO 1; (TV: Doctor Who and the Silurians) in the Doctor's seventh incarnation it read WHO 7, (TV: Battlefield) and WHO 8 in his eighth incarnation. (PROSE: The Dying Days) Miss Hawthorne referred to the Third Doctor as "the great wizard Qui Quae Quod"; those three words all mean "who" in Latin. (TV: The Dæmons) The aged Keeper of the Files referred to the Doctor with the name "Who". (PROSE: Doctor Who and the Doomsday Weapon)

The Fourth Doctor wrote a series of children's books during his time with UNIT which were mistakenly published under the name "Doctor Who": they were intended to be "The Doctor, Who Discovers Historical Mysteries", but the publishers presented it as "Doctor Who Discovers Historical Mysteries". (AUDIO: The Kingmaker)

K9 was heard on occasion making playful remarks related to the "Who" name. (TV: A Girl's Best Friend, Invasion of the Bane) Clive Finch's website called him "Doctor Who". (TV: Rose) Upon reading the Tenth Doctor's mind, Reinette remarked that "Doctor Who" was "more than just a secret". (TV: The Girl in the Fireplace) The oldest question in the universe was "Doctor Who?" (TV: The Wedding of River Song)

addressed a postcard to the Third Doctor as "Dr Who". (COMIC: Fogbound) later told Bill Potts that the Doctor's real name was "Doctor Who", before correcting herself to say that he had picked it in his childhood as an attempt to be mysterious, but that he had dropped the "Who" because it was "too on-the-nose". The Twelfth Doctor told Bill she was just trying to wind her up. He later identified himself as "Doctor Who" to Jorj, (TV: World Enough and Time) and told Missy that the name arose from the question of "who to save", calling it "the Doctor's Who". (COMIC: The Road To...)

The version of the Doctor in the Land of Fiction was known as Dr. Who. (PROSE: Prelude Conundrum, Conundrum, Head Games)

Theta Sigma
Theta Sigma, informally "Thete" and occasionally spelt "ΘΣ", was a nickname of the Doctor at the Time Lord Academy on Gallifrey. (TV: The Armageddon Factor, The Happiness Patrol, The Pandorica Opens) It identified him uniquely amongst the Time Lords and was not to be spoken outside of the Academy. (PROSE: Falls the Shadow) Despite this, both contemporaries of the Doctor (TV: The Armageddon Factor) and the Doctor themself mentioned the name while away from the Academy and Gallifrey. According to the author of The Time Lord Letters, a historical document compiling writings by and concerning the Doctor, "Theta Sigma" was also their Academy Student Identification Code. (PROSE The Time Lord Letters)

K9 was improved by Time Lord Theta Sigma. (PROSE: K9 and the Beasts of Vega)

Theta Sigma was part of River Song's message to the Eleventh Doctor on the universe's oldest cliff-face. (TV: The Pandorica Opens)

When the Doctor's final incarnation permanently died during the first battle of the War in Heaven, his coffin had two Greek letters on it; one of these was "Sigma". (PROSE: Alien Bodies)

In an alternate timeline in which Rassilon failed to finish the Eye of Harmony before his death, the Doctor never left Gallifrey and became a commentator rather than a renegade Time Lord. He was known as Commentator Theta Sigma. (AUDIO: Forever)

Oncoming Storm
The Doctor was referred to as the "Oncoming Storm" by the Draconians, (PROSE: Love and War) himself (PROSE: Vampire Science) and in "the ancient legends of the Dalek homeworld". (TV: The Parting of the Ways) In Draconian, the title was pronounced "Karshtakavaar". (PROSE: Love and War) After being told of the title by the Ninth Doctor, (TV: The Parting of the Ways) Rose Tyler called the Tenth Doctor by the "Oncoming Storm" when she and Mickey Smith were being prepared for dissection by the Clockwork Droids. (TV: The Girl in the Fireplace)

The Tenth Doctor later introduced himself as the "Oncoming Storm" to a Dalek aboard of the Wayfarer, (PROSE: Prisoner of the Daleks) and referred to the title when confronting a rabbit he thought was a Zygon. (TV: The Day of the Doctor)

The Eleventh Doctor began calling himself the "Oncoming Storm" when he misinterpreted Sean's request to help the King's Arms football team "annihilate" another team at a match. (TV: The Lodger) He later referred to the title when the Daleks forgot him. (TV: Asylum of the Daleks)

Destroyer of Worlds
As early as their second incarnation, the Doctor knew that the Daleks had also given them the epithet "Ka Faraq Gatri", (COMIC: Bringer of Darkness) which translated as "Destroyer of Worlds". (PROSE: Timewyrm: Revelation) or possibly, "Nice guy, if you're a biped". (PROSE: Continuity Errors) He had been awarded the name upon orchestrating the destruction of the Dalek home planet Skaro in his seventh incarnation, (TV: Remembrance of the Daleks) though the Daleks also used it prior to Skaro's destruction. (COMIC: Bringer of Darkness) Davros also referred to the Doctor as "the Destroyer of Worlds" after the Meta-Crisis Tenth Doctor destroyed the New Dalek Empire on the Crucible. (TV: Journey's End)

Known uses of John Smith

 * He used it as identification when renting the junkyard from its owner, Hawkins. (PROSE: The Rag & Bone Man's Story)


 * The name was on the First Doctor's library card while he was living at 76 Totter's Lane. (TV: The Vampires of Venice)


 * He used it when Rebecca Nurse asked his name, realising that a simple "Doctor" would not do. (PROSE: The Witch Hunters)


 * He used it to check in at Ingersoll's tavern in Salem. (PROSE: The Witch Hunters)

Other aliases

 * Dr Foreman: Addressed as "Dr Foreman" by Ian Chesterton due to the assumption that he shared Susan's (purported) surname. The Doctor responded, "Doctor who? What's he talking about?" (TV: An Unearthly Child) According to one source, however, he had previously used the alias while still on 1963 Earth during his trial for the killing of a werewolf. (PROSE: The Juror's Story)
 * Doctor I. M. Foreman: The Doctor's application for Susan Foreman's admittance into Coal Hill School used this alias. (PROSE: The Time Lord Letters)
 * Earl Foreman: When Barbara Wright was posing as Lady Barbara Foreman in the Victorian era, the Doctor posed as her father with the title of Earl. (PROSE: The Duke's Folly)


 * Wissfornjarl: While on the Isle of Hoy, Orkney in 1956, the Doctor was given this name by the spaywife Janet McKay. After seeing his arrival in the TARDIS, she mistook him for the island's protector from Norse mythology. He believed that it was simplest to accept the name. The name meant "Wise Old Chieftain," which Ian thought was appropriate. (AUDIO: The Revenants)


 * Benjamin Jackson: Used when he returned to the Salem Village on 18 July 1692. (PROSE: The Witch Hunters)


 * Doctor Caligari: The Doctor used it when he arrived in Tombstone, Arizona in October 1881, impersonating a magician. However, the locals mistook him for Doc Holliday. (TV: The Gunfighters)

Impersonations

 * Dr Samuel Smythe (PROSE: The Nine-Day Queen)


 * Maximus Pettulian: While visiting the Roman Empire shortly before the Great Fire of Rome in July 64, the Doctor briefly impersonated a murdered lyre player named Maximus Pettulian in the court of Nero. (TV: The Romans)


 * Zeus: When the Greek warrior Achilles mistook the Doctor for Zeus posing as an old man in circa 1200 BC, he went along with it, until the unconvinced Agamemnon spoiled the Doctor's ruse. (TV: The Myth Makers)

Nicknames

 * Snail / Wormhole: Given to him by his cousins of the House of Lungbarrow, because, unlike Loomed Gallifreyans, he had a bellybutton. (PROSE: Lungbarrow) The Hermit also called him this. (PROSE: The Three Paths)


 * Old-Man White-Hair: A nickname given to the First Doctor by Ace. (AUDIO: The Light at the End)


 * Pops: General Cutler disrespectfully called the Doctor this due to his old age. (TV: The Tenth Planet)


 * Mister Pastry: A name given to him by his twelfth incarnation who found his complaining funny. (TV: Twice Upon a Time)


 * Mary Berry: Called this by his twelfth incarnation after fleeing the Testimony Foundation's ship. (TV: Twice Upon a Time)
 * Corporal Jones: Called this by his twelfth incarnation as he prepared to head up into the tower on Villengard to confront Rusty. (TV: Twice Upon a Time)

Titles and epitaphs

 * The Traveller from Beyond Time: The epiphet given to the Doctor by the Elders. (TV: The Savages) It was later used as a name by the Seventh Doctor. (AUDIO: Afterlife)

Known uses of John Smith

 * The John Smith alias was given to him by Jamie, having seen a John Smith & Associates apparatus, and was used aboard Space Station W3. (TV: The Wheel in Space)
 * He later used it when questioned by Lt. Lucke, a German soldier in World War II. (TV: The War Games)

Other aliases

 * Gaius Iunius Faber: "Iunius Faber" being the Latin equivalent of John Smith. The Second Doctor used this alias during his visit to Bruttium, Italy in 71 BC. (PROSE: The Slave War)


 * Doctor Galloway: Edward Waterfield made up this name for the Second Doctor when arranging to meet him. (TV: The Evil of the Daleks)


 * Dr Rip Van Winkle: A name given to him by Mrs Craig. (PROSE: The Indestructible Man)


 * Citizen-Representative Henri Dupont (PROSE: World Game)


 * Doctor Jean Dupont (PROSE: World Game)


 * Doctor Mason: An alias used when he took part in a jury at the trial of the First Doctor for killing a werewolf. (PROSE: The Juror's Story)

Impersonations

 * The Examiner: Still not sure if he was "the Doctor" after his first regeneration, the Doctor took on the identity of an Examiner from Earth after the original one was assassinated by Bragen. (TV: The Power of the Daleks) Later in his life, he masqueraded as another Examiner, this time of a non-existing War Prison in an attempt to liberate Jamie from said prison. (TV: The War Games)
 * McCrimmon of McCrimmon: Jamie masqueraded as the hereditary chieftain of Jamie McCrimmon in order to deceive the War Chief into believing that he had successfully brainwashed McCrimmon. (TV: The War Games)
 * Napoléon Bonaparte (PROSE: World Game)

Nicknames

 * Clown: A nickname bestowed upon him by the First Doctor for his comical dress sense. (TV: The Three Doctors)


 * Beatles Haircut: A nickname given to the Second Doctor by Ace. (AUDIO: The Light at the End)


 * Archibald (PROSE: Fallen Angel)


 * Alphonse (PROSE: Fallen Angel)


 * Scarecrow: Spitefully used as a retort against his unkempt appearance by the Third Doctor in return for being called "fancy pants". (TV: The Five Doctors)

Titles and epitaphs

 * The Cosmic Hobo (PROSE: Beast of Fang Rock, The Dogs of War, The Enfolded Time)
 * The Comedian: A title given to the Second Doctor by for his comical personality. (GAME: Destiny of the Doctors)

Known uses of John Smith

 * The Third Doctor regularly called himself "John Smith" when working as UNIT's scientific adviser. (TV: Spearhead from Space, The Time Warrior)


 * He used it on the planet Kastopheria when asked by Administrator Charteris. (PROSE: Catastrophea)

Other aliases

 * Quiquaequod: Miss Hawthorne referred to the Doctor as "the great wizard Quiquaequod" while attempting to bluff the villagers of Devil's End into releasing him. (TV: The Dæmons) Later used in his seventh incarnation. (PROSE: Sanctuary)


 * Doctor Noble: An alias used when he took part in a jury at the trial of the First Doctor for killing a werewolf. (PROSE: The Juror's Story)


 * Prisoner 177781: The Doctor was recorded by this designation when he was briefly arrested by the British Army alongside Sarah Jane Smith, who was recorded as Prisoner 177782. (TV: Invasion of the Dinosaurs)

Impersonations

 * : Forced to masquerade as the Master when the latter switched bodies with him. (PROSE: The Switching)


 * El Llama (PROSE: Catastrophea)

Nicknames

 * Dandy: A nickname bestowed upon him by the First Doctor for his upper-class attire. (TV: The Three Doctors)


 * Thedoct>Orism: The Doctor's title as interpreted by the Siccati. It could be shortened to Thedoct. (PROSE: Neptune, Sedna)


 * Frilly Shirt: A nickname given to the Third Doctor by Ace. (AUDIO: The Light at the End)


 * Fancy Pants: An insult used by the Second Doctor to get a parting shot in at his successor's appearance before the incarnations went their separate ways. (TV: The Five Doctors)

Titles and epitaphs

 * The Great Healer (PROSE: The Spear of Destiny)


 * The Time Warrior (PROSE: A Soldier's Education)

Known uses of John Smith

 * A French variation, "Brigadier-General Jean Forgeron," was used by the Doctor when met by French soldiers in the labyrinth underneath Paris. (COMIC: The Forgotten)


 * He used the name in Budapest in 1980. (AUDIO: The Labyrinth of Buda Castle)


 * Figment knew the Fourth Doctor by the name "Jonathan Smith". (PROSE: Afterwords)

Other aliases

 * ?: The Doctor signed a document with a question mark prior to the Sontaran invasion of Gallifrey. (TV: The Invasion of Time)


 * Drax (COMIC: Time Lady of Means)

Impersonations

 * Hieronymous: Stole Hieronymous's robes and pretended to be him to defeat the Mandragora Helix. (TV: The Masque of Mandragora)


 * Doctor Svengali (PROSE: Ghost Ship)


 * Oskin: The Doctor masqueraded as Oskin in order to destroy The Asteroid. (AUDIO: Requiem for the Rocket Men)

Nicknames

 * Long-Scarf Big-Eyes: A nickname given to the Fourth Doctor by Ace. (AUDIO: The Light at the End)


 * Master: K9's affectionate nickname for the Doctor. (TV: The Invisible Enemy)


 * Teeth and Curls: Referred to this by the Ninth Doctor to identify this incarnation while speaking to his tenth and twelfth incarnations. (COMIC: The Lost Dimension)


 * Scarfy Me: Addressed as such by the Thirteenth Doctor. (WC: Doctors Assemble!)

Titles and epitaphs

 * The Bohemian / The Wanderer: Titles given to the Fourth Doctor by the Master. (GAME: Destiny of the Doctors)


 * The Evil One: The Sevateem tribe referred to the Doctor as "the Evil One". Xoanon, the supercomputer which they worshipped, had two personalities, one of which was based on the Fourth Doctor. (TV: The Face of Evil)


 * The Wizard: Emily, a child in whom Leela was reborn after her death, referred to the Doctor as "the Wizard." (AUDIO: The Child)

Known uses of John Smith

 * On Folly, the Fifth Doctor was believed to be a criminal mastermind known as Dr John Smith. (AUDIO: Doing Time)


 * The Fifth Doctor used the name when he worked as a historical advisor on the short film The Devil's Whisper, the first of the constituent short films of the 1976 portmanteau film Doctor Demonic's Tales of Terror. (AUDIO: Special Features)


 * The Fifth Doctor used the name when in Reykjavik on 12 February 2144. (AUDIO: Repeat Offender)


 * The Fifth Doctor used it on both the Confederate and Union sides of the American Civil War as a guise under which he could render medical assistance, while having the freedom to search for his lost companions, Peri and Erimem. He received some local publicity under the name after delivering the baby of the mayor of Gable, West Virginia. He was personally known to Abraham Lincoln by this name after he had saved the president's life during an assassination attempt in Richmond, Virginia. (PROSE: Blood and Hope)


 * At the First Doctor's trial in 1963, the Fifth Doctor used the name Dr Smith as part of the jury. (PROSE: The Juror's Story)

Other aliases

 * Gaius Claudius Maximus: The Doctor used this name while visiting Cumae in 63 BC. (AUDIO: Tartarus)


 * Doctor Walters: The Doctor used this name while stuck in Victorian London without his TARDIS for a year from November 1866 to 1867. (AUDIO: The Haunting of Thomas Brewster)


 * Dr Jonas Smythe: The Doctor used this name when working with Liz Shaw in Italy. (PROSE: Flashpoint)


 * The Supremo: The Doctor called himself "the Supremo" while leading the alliance against the army of the renegade Time Lord Morbius. Originally, his title was "Supreme Controller", but the Ogrons of his personal guard could not pronounce it and shortened it to the simpler "Supremo". (PROSE: Warmonger)

Impersonations

 * Dr. Sebastian Rowley (PROSE: A Town Called Eternity)

Nicknames

 * Cricket Boy: A nickname given to the Fifth Doctor by Ace. (AUDIO: The Light at the End)


 * Demon: Called so by Kamelion, while the android was disguised as King John of England. (TV: The King's Demons)

Known uses of John Smith

 * "jsmith" was the Sixth Doctor's username online. (PROSE: Blue Box)


 * When he was arrested for trespassing at Greenstreet Police Station in 1974, the Doctor gave his name as "Dr John Smith". (AUDIO: Urgent Calls)


 * The Doctor sent an email signed "Smith, Dr. John" to young girl to warn her of Mr. Silhouette. (PROSE: Academic Notes)


 * He also used it to infiltrate the Dominus Institute in 2016. (AUDIO: Vampire of the Mind)


 * In Lancashire in the 19th century, the Doctor introduced himself as "Dr John Smith" to Samuel Belfrage. (AUDIO: Industrial Evolution)


 * When infiltrating the Third Reich to investigate the origins of the Fourth Reich in 2001, he made fake credentials identifying himself as Major-General Johann Schmidt of the Berlin Fifth Medical Corps. (PROSE: The Shadow in the Glass)


 * The Doctor used the name while working in Hut 12A at Bletchley Park in 1944. (AUDIO: Criss-Cross)


 * He also used the name while posing as a British SIS agent in Vienna in 1948. (AUDIO: Quicksilver)


 * In 1957, the Sixth Doctor and Melanie Bush investigated UFO sightings in the proximity of Hammerston, Louisiana and became involved in the production of the film Swamp of Horrors after attacking an actor in a rubber alien suit whom they mistook for a genuine alien. The Doctor, who used the pseudonym "John Smith", and Mel were assumed to be uncredited actors playing fictional characters by film critics. (PROSE: Swamp of Horrors (1957) - Viewing Notes)

Other aliases

 * Professor Erasmus Potgeiter of Pretoria Scientific Institute (PROSE: Players)


 * Patient #58204 (COMIC: Façades)


 * Nico Blair: Briefly used when trying to convince Carburetor that the Piscons were part of a television prank. Nico Blair was supposedly an expert on alien special effects. (AUDIO: Peri and the Piscon Paradox)


 * Albert Einstein: Used by the Doctor while meeting with Charles Darwin in the Galápagos Islands in 1835. (AUDIO: Bloodtide)


 * The Sandman: Adopted as part of a plan to stop an alien race attacking others by inspiring the idea of him as a monster. (AUDIO: The Sandman) It was later used as a name by the Seventh Doctor. (AUDIO: Afterlife)


 * Professor Claudius Dark: Used while the Doctor was undercover in the 19th century, so as to avoid the attention of Mr Kempston and Mr Hardwick (AUDIO: The Hourglass Killers) as well as Queen Victoria. (AUDIO: Jago & Litefoot Forever)


 * Mr Nocturne: Used when he arrived a few days early after receiving a message from Henry Gordon Jago and Professor George Litefoot. (AUDIO: Masterpiece)

Impersonations

 * Dr Grigori Kalashnikov: The Doctor adopted the identity of a Moscow University scientist when he arrived at the Baikonur Cosmodrome in Kazakhstan on 10 November 1963. (AUDIO: 1963: The Space Race)


 * Zarl: After the Doctor had chased him to his death, the Doctor impersonated Zarl to maintain the Web of Time and his previous incarnation's meeting with Zarl. (AUDIO: Peri and the Piscon Paradox)


 * Captain Jack Harkness: Posed as Jack when the latter's impersonation of the Doctor landed him in trouble. (AUDIO: Piece of Mind)


 * Banto Zame: Posed as Zame when the latter's impersonation of the Doctor landed him in trouble. (AUDIO: The One Doctor)

Nicknames

 * Joseph: A nickname given to the Sixth Doctor by Ace. (AUDIO: The Light at the End)


 * Old One: Given by Balazar while investigating Ravolox. The Doctor took offence, as by Gallifreyan terms, he was actually still quite young. (TV: The Mysterious Planet)


 * Mr. Rainbow Coat (AUDIO: The Rani Elite)

Titles and epitaphs

 * jeoffrey (PROSE: Blue Box)


 * Merryman (PROSE: Blue Box)


 * Doktor of TARDIS: Used by the Sixth Doctor to move discreetly around an alternate version of the city of Rome. (PROSE: State of Change)


 * Lazarus: The code-name that the Forge used to refer to the Sixth Doctor. (AUDIO: Project: Lazarus; PROSE: Project: Valhalla)


 * The Dark One / He Whose Name Dare Not Be Mentioned: Names given to the Sixth Doctor/the Valeyard in the legends of the Great Kingdom, an unstable alternate version of London created by the botched summoning of Saraquazel. (PROSE: Millennial Rites)

Known uses of John Smith

 * He pretended to be a "Dr. John Smith" sent to replace Dr. Lewis. (COMIC: Cat and Mouse)


 * He used the German variation "Johann Schmidt" while impersonating the Reichsinspektor General. (PROSE:  Timewyrm: Exodus)


 * The Doctor opened an account at Coutts Bank in 1868 with the name "R. J. Smith Esq.". (PROSE:  Birthright)


 * The Seventh Doctor was known as "the Infamous General Smith" by the Sontarans. (PROSE: Shakedown)


 * The Seventh Doctor referred to himself as Doctor John Smith, a governmental official, when he introduced himself to Peggy Marsden and Albert Marsden. (AUDIO: Protect and Survive)


 * He again used "Johann Schmidt" when posing as Schumacher's superior. (AUDIO: Protect and Survive)


 * Johannes Smither: (AUDIO: Kingdom of Silver)

Other aliases

 * Commander John Ballard: The Doctor was mistaken for the new commander of Dark Space 8 after he and Melanie Bush were teleported aboard the station following the destruction of Ballard's shuttle. (AUDIO: Bang-Bang-a-Boom!)


 * ?: The Doctor signed a document with a question mark during a visit to London in 1963. (TV: Remembrance of the Daleks)


 * John Rutherford: Using this pseudonym, the Doctor was elected as an independent member of Parliament in May 1963 on a platform of nuclear disarmament. (AUDIO: 1963: The Assassination Games)


 * Merlin: The Doctor was mistaken by the people from an alternate universe which inspired the Arthurian legend to be Merlin, (TV: Battlefield) due to the Eighth Doctor using the alias when delivering King Arthur. (PROSE: One Fateful Knight)


 * Norman Brown: Used, with a West Country accent, to hide his identity from Sheldukher. (PROSE: The Highest Science)


 * Jean Forgeron de Gallifrey: Used with the title of "Royal Observer from the court of Alexander". (PROSE: Sanctuary)


 * Billy Spot: Used to infiltrate Gordy Scraton's organisation, with a London accent for further disguise. (PROSE: Bad Therapy)


 * Isha: Used while in 1560 Japan. (PROSE: The Room With No Doors)


 * Pendragon: Used when undercover as leader of the Triad organisation Tao Te Lung. (PROSE: Bullet Time)


 * Septimus Doctus: Used when visiting Julius Caesar. (COMIC: Crossing the Rubicon)


 * Dr Vaughn Sutton: Used on Perfugium, (AUDIO: Master) based on an alias used by Lord Grayvorn. (AUDIO: Excelis Decays)


 * Richard A. Fells: The Doctor used this name while posing as a prisoner in Alcatraz. (PROSE: Inmate 280)


 * Mr Ashcroft: The Doctor used this name to acquire recordings from Bianca's. (AUDIO: The Wormery)


 * John Doe: The customary name in America for an unidentified human male was applied to the apparently dead Doctor by the staff of Walker General Hospital, and he was given a "John Doe" toe tag before being wheeled into the morgue's freezer, where he subsequently regenerated into his eighth incarnation. At no point did the Doctor use this alias himself. (TV: Doctor Who)

Impersonations

 * Ea: After Gilgamesh assumed him to be the god of wisdom, Ea, the Doctor decided to go along with it. (PROSE: Timewyrm: Genesys)
 * Dr. Dumont-Smith: (PROSE: Loving the Alien)

Nicknames

 * Professor: Ace called the Doctor this instead of his preferred name. (TV: Dragonfire et al.)

Titles and epitaphs

 * Time's Champion: A title given to the Doctor for his service to Time during his seventh incarnation, (PROSE: Love and War) which was unique only to the Seventh Doctor. (PROSE: The Room With No Doors)


 * Star Traveller: Referred to a such by William Blake. (PROSE: The Pit)


 * The Umbrella Man: After he rewrote her history, Elizabeth Klein referred to him as such given she was not aware of his identity. (AUDIO: Dominion)


 * The Scottish Doctor: When Honoré Lechasseur once met the Doctor, he described him as such, as well as sporting a beard. (PROSE: The Cabinet of Light)


 * The Destroyer of Skaro: Among the names for the Doctor recorded by the Testimony, (TV: Twice Upon a Time) in reference to the Hand of Omega's destruction of Skaro as planned by the Seventh Doctor. (TV: Remembrance of the Daleks)


 * The Evil Renegade: The name known to former companions brainwashed by the Great Houses. (PROSE: Dead Romance, Judy's War)


 * Mister Seven: The name used by Septimus and his fellow Cwejen for their memories of the Doctor as a "pale god". (AUDIO: The Adventure of the Diogenes Damsel)

Known uses of John Smith

 * In a timeline where the Nazis won World War II, an alternative version of the Eighth Doctor also used the German variation. (AUDIO: Colditz, Klein's Story)


 * He used the German variation "Johann Schmidt" while posing as a German spy. (AUDIO: Storm Warning)


 * He once called himself "Professor Smith". (PROSE: The Heroine, the Hero and the Megalomaniac)


 * "Jsmith8" was the Eighth Doctor's username online. (PROSE: Lonely)


 * He introduced himself to Dal, an amnesic Dalek, as "John Smith", in order to prevent Dal's true memories being triggered by reference to his true identity. (AUDIO: Echoes of War)

Other aliases

 * John Doe: In a continuation of the circumstances described above for the Seventh Doctor, the Eighth Doctor was referred to by this name after his escape from the morgue was discovered. (TV: Doctor Who)


 * Dr James Alistair Bowman: Dr Grace Holloway came up with the name "Dr Bowman" for the Eighth Doctor whilst introducing him to others at the New Year's Eve party. (TV: Doctor Who)
 * The Doctor subsequently used this alias on occasion, filling it out to James Alistair Bowman. (PROSE: Seeing I, Unnatural History, Frontier Worlds)
 * He used the name again while at the First Doctor's trial for the killing of a werewolf. (PROSE: The Juror's Story)


 * Merlin: The Doctor took up the alias to deliver King Arthur in another reality. (PROSE: One Fateful Knight) Later, whilst stuck in the otherworld of Avalon, the Doctor attempted to pass himself off as Merlin to Queen Mab. (PROSE: The Shadows of Avalon)


 * Doctor Doctor: Inadvertently introduced as such when talking to Doctor Charles Roley and his staff; Sam Jones dismissed it as an amusing irony, with the Doctor explaining that this was why he preferred to just be known as "Doctor". (PROSE: The Taint)


 * Dr Jack-of-the-Moon: This was a term meaning those who concentrated on high-minded things at the expense of the normal world. It was used to refer to the Doctor (for example, on his marriage invitation) during his time on Henrietta Street. (PROSE: The Adventuress of Henrietta Street)


 * Perdix: While in Rhadamanthys' court. (PROSE: Fallen Gods)


 * Blessed Destroyer: Erasmus told Chloe that their world had been destroyed by the Blessed Destroyer. (PROSE: Timeless)


 * Gracie Witherspoon: To defeat the Threshold, the Doctor used a personal chameleon circuit to take the appearance of a female Threshold agent while Shayde masqueraded as the Doctor. (COMIC: Wormwood)


 * Dr Frankenstein: When meeting Mary Shelley and the other inhabitants of Villa Diodati in Switzerland, the half-delirious Doctor introduced himself this way. (AUDIO: Mary's Story)


 * Ambrosius Clemenses: An alias used in 305, with Charley being "Dasia Dasia". (AUDIO: Seasons of Fear)


 * Reverend Doctor of Bruges: An alias used in 1055, with Charley being "Lady Charlotte". (AUDIO: Seasons of Fear)


 * Sir Doctor Peter Pollard: When he arrived at Sebastian Grayle's 19th-century manor house, with Charlotte Pollard pretending to be his daughter. (AUDIO: Seasons of Fear)


 * Bert Higgins: While on Nixyce VII. (AUDIO: The Traitor, Eyes of the Master)


 * Dr Foster: To hide his identity from Nyssa, he introduced himself as Dr Foster from the planet Gloucester, famous for its rains and huge puddles. (AUDIO: A Heart on Both Sides)


 * Captain Jonah: While serving as captain on the Bloodhound during the Time War. (AUDIO: Jonah)

Impersonations

 * Dr Kepesk: (PROSE: Kursaal)


 * Dr Friedlander: While visiting Banquo Manor, he assumed the name of a real Doctor Friedlander who hadn't arrived at the Manor in order to avoid having to explain his presence. (PROSE: The Banquo Legacy)


 * Klenton Dewfurth: (PROSE: Frontier Worlds)


 * Dr Domecq: When impersonating a representative of Earth Central. (PROSE: Dark Progeny)


 * Doctor Jack Halliday: The Doctor was mistaken for the real Jack Halliday after finding his body and deciding to look in his office for clues about what happened to him. The original Halliday was not a doctor, but Charley referred to him as such and the Doctor claimed that he just didn't advertise the title to avoid giving people the wrong idea. (AUDIO: Invaders from Mars)


 * The Clocksmith: To hide his identity from a possible future incarnation, the Doctor used a psychic wimple to pretend to be the Clocksmith. (AUDIO: The Crucible of Souls)

Nicknames

 * Skipper: The Doctor's companion Samson Griffin always referred to him as such. (AUDIO: Terror Firma)


 * Lord Byron: A nickname given to the Eighth Doctor by Ace. (AUDIO: The Light at the End)


 * Tigger / Eeyore: When the Doctor is split into three, each bearing different parts of his personality, Charley Pollard gave these nicknames to the bouncy and excitable, and the surly and ruthless Doctors. (AUDIO: Caerdroia)

Titles and epitaphs

 * The Eighth Man Bound: The Doctor referred to himself as this name, (PROSE: The Dying Days) based on the fact that the Doctor was the only student to see a glimpse of his future right up to his eighth incarnation in the Eighth Man Bound game. (PROSE: Lungbarrow, Christmas on a Rational Planet)


 * Life's Champion (PROSE: Vampire Science)


 * Doctor Know-All (PROSE: Grimm Reality)


 * Evergreen Man: The name given to him by the Sidhe. (PROSE: Autumn Mist)


 * The Professional (PROSE: Fear Itself)

Known uses of John Smith

 * The War Doctor used the name John Smith to introduce himself to Garv on Keska. (AUDIO: The Thousand Worlds)


 * He also used the name when introducing himself to Coyne, as he did not wish for his Time Lord heritage to be discovered. (PROSE: Engines of War)

Other aliases

 * Prisoner 101: A designation given to him by Cardinal Ollistra when she arrested him as a war criminal. (AUDIO: Legions of the Lost)


 * Stowaway: Rosata Laxter called him this repeatedly after discovering the Doctor on her ship, when she heard others refer to him by his former title, he insisted she continued calling him "Stowaway". (AUDIO: The Lady of Obsidian)

Nicknames

 * Greybeard: A descriptive name given to him by Kalan during the rescuing operation on Rovidia. (AUDIO: The Eternity Cage)


 * The Mad Fool: A nickname given by the General, since the War Doctor was working against the Time Lords' plans and seemingly ensuring their destruction. (TV: The Day of the Doctor)


 * Grandad: A nickname given by the Eleventh Doctor due to the War Doctor's aged appearance. (TV: The Day of the Doctor)


 * Captain Grumpy: A nickname given by the Eleventh Doctor due to the War Doctor's serious personality. (TV: The Time of the Doctor)

Titles and epitaphs

 * The Warrior: The moniker the Doctor chose to take in the Fifth Segment of the Time War upon his eighth regeneration, (PROSE: The Stranger) and his rejection of his "Doctor" title. (TV: The Night of the Doctor) By the time he went back to the First Segment of the war, he had stopped calling himself a warrior as well. (PROSE: The Stranger) Clara Oswald later referred to him as "the Warrior" to differ himself from the Tenth and Eleventh Doctors. (TV: The Day of the Doctor)


 * The Lord of Death: One of the Volatix Cabal identified the Doctor as such during the Time War. (COMIC: The Organ Grinder)


 * The Predator of the Daleks: A descriptive term for the Doctor used by the Daleks, (TV: Asylum of the Daleks) that originated during his war incarnation. (PROSE: Engines of War, Decoy)


 * The Deathbringer: A title bestowed upon the Doctor by the Daleks during the Time War. (PROSE: Decoy)


 * The One Without Mercy: A title bestowed upon the Doctor by the Daleks during the Time War. (PROSE: Decoy)


 * Dalek Killer: One of the names awarded to the War Doctor by the Daleks. (PROSE: Engines of War)


 * The Great Scourge: One of the names awarded to the War Doctor by the Daleks. (PROSE: Engines of War)


 * The Living Death: One of the names awarded to the War Doctor by the Daleks. (PROSE: Engines of War)


 * The Executioner: One of the names awarded to the War Doctor by the Daleks. (PROSE: Engines of War)


 * The Renegade: A name the Time Lords used to refer to the War Doctor as he planned to use the Moment to end the Last Great Time War. (COMIC: Sky Jacks)


 * The Doctor of War: A name that arose as part of a saying used to describe him during the Time War that was recorded by the Testimony. (TV: Hell Bent, Twice Upon a Time)


 * The Butcher of Skull Moon: Among the names for the Doctor recorded by the Testimony, (TV: Twice Upon a Time) in reference a battlefield attended by the War Doctor during the Last Great Time War. (TV: Hell Bent)

Known uses of John Smith

 * The name Doctor as "Dr John Smith" on a piece of psychic paper during the Ninth Doctor's visit to 1941. (TV: The Empty Child)


 * While imprisoned at Hesguard Institute, the Doctor wore a jumpsuit identifying him as "J. Smith". (COMIC: Sin-Eaters)

Other aliases

 * Brigadier Bambera: Used when visiting the Christmas truce of World War I. (COMIC: The Forgotten)


 * Mr Spock: Rose Tyler, annoyed with the Doctor not telling her his name, introduced him to Captain Jack as Mr Spock. (TV: The Empty Child)


 * Doctor Table: Used while trying to get a Neanderthal out of a hospital, claiming to be an expert in a rare disease that the man was suffering from. (PROSE: Only Human)


 * Patient 280: His given alias during his imprisonment at Hesguard Institute. (COMIC: Sin-Eaters)


 * Hal Gryden: While on the planet Arkannis Major, the Doctor adopted the name of this fictional newscaster to broadcast a message of peace to the people of the world. (PROSE: The Stealers of Dreams)


 * Inspector George Dixon: Used when helping the police department on 23rd century New Vegas with their investigation into the Whisper. (AUDIO: Night of the Whisper)

Nicknames

 * The Navvie: Honoré Lechasseur's nickname for the Doctor, due to his leather jacket. (PROSE: The Albino's Dancer)


 * U-boat Captain: A snide nickname given by Captain Jack, who mocked the Ninth Doctor's leather jacket, which made him look like a German officer. (TV: The Empty Child)


 * Larry: Called this by Jackie Tyler after being ordered to close the TARDIS doors. (COMIC: Supremacy of the Cybermen)


 * Muggins: Jackie Tyler uses this name to refer to the Doctor after the TARDIS central console exploded. (COMIC: Supremacy of the Cybermen)


 * Big Ears: Mickey Smith describes the Ninth Doctor in this way, causing the latter to believe Mickey was saying he wasn't handsome. (TV: Boom Town)


 * Me with the ears: The Tenth Doctor called him this to address him directly. (COMIC: The Lost Dimension)


 * Marley's Ghost: In reference to Jacob Marley of A Christmas Carol, his Matrix projection is called this by the Tenth Doctor when he makes a comment about the latter's changing after the Time War. (COMIC: The Forgotten)


 * Big Nose: The Tenth Doctor refers to this incarnation as such when questioning the Alternate Twelfth Doctor about his whereabouts. (COMIC: Four Doctors)

Titles and epitaphs

 * The Final Judgement: Title used by Addison Delamar when auctioning off the Doctor's memories. (COMIC: The Bidding War)


 * The Prophet: Called so by Father Heretika, a representative of the Church of the Evergreen Man, a race who believed the Doctor to be a messiah. (COMIC: The Bidding War)


 * The Great Exterminator: The name given to the Doctor by the Dalek Emperor whilst preparing a Delta Wave. (TV: The Parting of the Ways)


 * The Great Destroyer: Another name given to the Doctor by the Dalek Emperor, whilst taunting the Doctor to use his Delta Wave. (TV: The Parting of the Ways)


 * The Heathen: Another name given to the Doctor by the Dalek Emperor. (TV: The Parting of the Ways)

Known uses of John Smith

 * The Tenth Doctor used the name while working undercover as a science teacher at Deffry Vale High School. (TV: School Reunion)


 * He also used it while posing as a patient at Royal Hope Hospital (TV: Smith and Jones)


 * He used the name "Dr. John Smith, opto-mechanical technician for the Imperial College [of] London" to gain access to the Griffith Observatory. (COMIC: Quiet on the Set)


 * The Tenth Doctor told Professor Conrad Morris that his name was John Smith in 2088. (PROSE: Breathing Space)


 * The Tenth Doctor used the name while impersonating a health and safety officer during an investigation of Adipose Industries. (TV: Partners in Crime)


 * While at Eddison Manor after the murder of Professor Gerald Peach, the Tenth Doctor claimed to be Chief Inspector Smith of Scotland Yard in order to keep the police out of what he suspected to be an alien crime. (TV: The Unicorn and the Wasp)


 * The Tenth Doctor attempted to use the alias aboard the Crusader 50 bus on the planet Midnight when asked for his name, but it was recognised as a false name and rejected by the panicking humans aboard. (TV: Midnight)


 * He used it when reintroducing himself to Donna Noble after he erased her memories of him. (TV: Journey's End)


 * He used it when encountering Jackson Lake, a man who, due to Infostamp exposure, believed himself to be an incarnation of the Doctor. (TV: The Next Doctor)


 * The Tenth Doctor introduced himself as John Smith to Cleo. (COMIC: The Fountains of Forever)


 * He used the alias "Dr. John Smith" when he claimed to be replacing Dr. Bell from the Inspectorate. (COMIC: The Lost Dimension)


 * The Tenth Doctor used the alias while pretending to be a manager of the Brainy Crisps industry. (PROSE: Code of the Krillitanes)

Other aliases

 * Doctor James Robert McCrimmon: The Tenth Doctor briefly called himself Dr James McCrimmon of Balamory while visiting Scotland in 1879. Later, he dropped the alias and was knighted by Queen Victoria as "Sir Doctor of TARDIS". (TV: Tooth and Claw) He again used the alias when writing a letter to Mr. Finch recommending himself "Dr. John Smith" to teach at Deffry Vale High School. (PROSE: The Time Lord Letters)


 * Doctor Jones (PROSE: The Nightmare of Black Island)


 * Luigi Barver (AUDIO: The Sword of the Chevalier)


 * Doctor Vile: The Doctor briefly masqueraded as the space pirate Doctor Vile to stop a war between humans and intelligent insects. (TV: The Infinite Quest)


 * Doctor Donald Duck (PROSE: Martha in the Mirror)


 * Baronet Jones of Nova Scotia (PROSE: The Many Hands)


 * Spartacus: When visiting Pompeii in 79 A.D, the Doctor and Donna both called themselves 'Spartacus', which had been a minor joke. Lobus Caecilius mistook this as them being siblings. (TV: The Fires of Pompeii)


 * Doctor Noble: The Doctor used this when investigating the Ood Industries claiming that he and Donna were from the Noble Corporation. (TV: Planet of the Ood)


 * Doctor McCoy: After a discussion with Donna Noble, in which she compared the sonic screwdriver to Star Trek's tricorder, the Doctor used the alias Dr McCoy (after Dr Leonard "Bones" McCoy) when dealing with a group of soldiers (Donna called herself Captain Kirk, after James T. Kirk). (AUDIO: Pest Control)


 * Chief Inspector Smith from Scotland Yard: Used when involved with the death of Professor Peach. (TV: The Unicorn and the Wasp)


 * Dr. Johannes Schmidt (PROSE: Autonomy)


 * Doctor Venkman: In New Orleans during Jazz Age. (COMIC: The Jazz Monster)


 * Actors: When visiting Hollywood in the early 20th century, the Doctor adopted a number of Hollywood-related names whilst attending a party. Within the space of a few minutes, he called himself "Tom Cruise", "Michael Caine", "Pee-Wee Herman" and "Tom Hanks". (COMIC: Silver Scream)

Nicknames

 * Martian Boy: Donna Noble once called the Doctor by this name, earning his protests that he was not from Mars. (TV: The Runaway Bride)


 * Gramps: once called the Doctor this name as a joke towards his old age. (TV: Last of the Time Lords)


 * Gandalf: once called the Doctor this name as a joke. (TV: Last of the Time Lords)


 * Spaceman: Donna Noble often called the Doctor by this name and Christina de Souza also referred to the Tenth Doctor by this as well. (TV: The Fires of Pompeii, Planet of the Dead)


 * Mr Conditional Clause: A nickname given by a frustrated Luke Rattigan after the Doctor said "ATMOS system" as a clapback because "ATMOS" meant "Atmospheric Omission System" and the Doctor would, according to Luke, be saying "Atmospheric Omission System system". This was because Luke earlier had said to the thought of moving to other planets "if only that was possible" and the Doctor corrected him saying "if only that were possible", saying it was a "conditional clause". (TV: The Sontaran Stratagem)


 * Pretty Boy: Used by River Song the first time he meets her from his point of view. (TV: Silence in the Library, Forest of the Dead)


 * Baby Doctor: The Twelfth Doctor referred to this incarnation as such when fearing he would be "Scary Doctor". (COMIC: Four Doctors)


 * Doc-Dude: Referred to as such by Cindy Wu after the Doctor forbade her from calling him "Baby", "Buster" and "Dude". (COMIC: Lady of the Blue Box)


 * Bambi: The Twelfth Doctor called the Tenth this due to his large brown eyes. (COMIC: Vortex Butterflies)


 * Merlin: The Tenth Doctor claimed that he was called Merlin by King Arthur. (COMIC: Fugitive)


 * Matchstick Man: A nickname given to him by his successor upon noticing that he had been exceptionally thin. (TV: The Day of the Doctor)


 * Daddy's Suit: The War Doctor's nickname for the Eleventh Doctor, due to his dress sense. (PROSE: The Day of the Doctor)


 * Sandshoes: A mocking nickname given to him by the Eleventh Doctor in reference to his choice of footwear. (TV: The Day of the Doctor)


 * Dick van Dyke: Another mocking nickname given by the Eleventh Doctor, after the Tenth commented on the War Doctor's gravelly voice. (TV: The Day of the Doctor)

Titles and epitaphs

 * Sir Doctor of TARDIS: After saving her from an assassination, the Doctor was knighted by Queen Victoria as "Sir Doctor of TARDIS". (TV: Tooth and Claw) The Doctor later tried to use the title when he met William Shakespeare. (TV: The Shakespeare Code)


 * Dark Lord: Dalek Caan once referred to him as the Dark Lord in his prophecy. (TV: The Stolen Earth)
 * Time Lord Victorious: A title the Tenth Doctor briefly claimed after interfering with a fixed point in time and saving Adelaide Brooke from her death. When Adelaide killed herself to restore the timeline, causing several changes that the Tenth Doctor instantly saw because of what he had done, the Tenth Doctor was filled with extreme guilt and horror over what he did, quickly abandoning the "Time Lord Victorious" title. (TV: The Waters of Mars)


 * The Hero: The word Clara Oswald used to best describe what kind of person the Tenth Doctor was trying to be like. (TV: The Day of the Doctor)


 * Number Ten: Used by the Eleventh Doctor when discussing his regeneration cycle with Clara Oswald. (TV: The Time of the Doctor)

Known uses of John Smith

 * The Doctor called himself "Agent John Smith, AKA the Doctor, of Scotland Yard" while investigating in 1896 San Francisco. (COMIC: The Steampunk Conundrum)


 * The Eleventh Doctor took the place of a real Dr Schmidt when his psychic paper displayed the credentials of a visitor expected at the Lexington Bank. (PROSE: Borrowed Time)


 * He used it while posing as his Ganger counterpart as an independent name for himself. (TV: The Almost People)


 * The Doctor introduced himself as Dr Smith, and Clara as his wife, to Mrs Gillyflower to try and infiltrate Sweetville in 1893. (TV: The Crimson Horror)

Other aliases

 * Captain Troy Handsome of International Rescue: When introducing himself to a crashed time ship's avatar. (TV: The Lodger)


 * Commander Bond of Naval Intelligence: An alias used by the Doctor when he encountered Gein. (COMIC: Sub-species)


 * Bob Moss (PROSE: Horror of the Space Snakes)


 * Fred Astaire: An alias he used when asked to sign his name for a magic show audition. (PROSE: Magic of the Angels)


 * Mr Lineker from the Fair Organisation Of Football Agency: An alias the Doctor's psychic paper created when he sought to enter Wembley Stadium for the 1966 World Cup Final. (PROSE: Extra Time)


 * Jean Valjean: Alias used by the Doctor to infiltrate Alcatraz as a prisoner. (COMIC: Escape into Alcatraz)
 * Roy Robins: Alias used while prolonging his death. (PROSE: Who Isn't Who?)


 * The Caretaker: Alias used when Madge, Lily and Cyril Arwell stayed with him in a dilapidated house in Dorset. (TV: The Doctor, the Widow and the Wardrobe)


 * Sherlock Holmes: Used to gain entry to Dr Simeon's institute. Strax even called the Doctor this a few times just to annoy him. (TV: The Snowmen)


 * Proconsul: Alias used during his adventure at Hedgewick's World of Wonders to keep a punishment platoon from being hostile to him and his guests. (TV: Nightmare in Silver)


 * Elias: An alias the Doctor used when introducing himself to Ssardak on Trenzalore. (PROSE: Let it Snow)

Impersonations

 * Colonel Lethbridge-Stewart (PROSE: Shroud of Sorrow)

Nicknames

 * Mr. Moon: A descriptive name the Doctor gave himself after first examining his new face. (PROSE: The Day of the Doctor)


 * Sweetie: Frequently used by River Song as a dual greeting and affectionate nickname. (TV: The Time of Angels, et al.)


 * Space Gandalf: When questioned by Amy as to what kind of person he's like, the Doctor answered that he was like a "Space Gandalf". (TV: Meanwhile in the TARDIS 2)


 * Ancient Amateur: The Doctor described himself as such to Craig Owens. (TV: The Lodger)


 * Caesar: A Roman Auton, under the influence of River Song's hallucinogenic lipstick, in 102 A.D., mistook the Doctor for Caesar. (TV: The Pandorica Opens)


 * My Love: A term of affection River Song used for the Doctor. (TV: The Pandorica Opens)


 * Bowtie me: The Tenth Doctor referred to this incarnation to his companions. (COMIC: Four Doctors)


 * Posh Doctor: The Twelfth Doctor referred to this incarnation as such when fearing he would be "Scary Doctor". (COMIC: Four Doctors)


 * Legs Eleven: Called this by the Twelfth Doctor when referring to this incarnation to Gabby Gonzalez. (COMIC: Four Doctors)


 * Laughing Boy: Referred to as this by the Ninth Doctor, after the Eleventh Doctor was found trapped in a Type One TARDIS. (COMIC: The Lost Dimension)


 * Time Boy: Used by Mels, the second incarnation of River Song, as she anticipated meeting the Doctor while growing up with her parents in Leadworth. (TV: Let's Kill Hitler)


 * Also Not Mum: Called this by Alfie Owens in 2011. (TV: Closing Time)


 * The Chin: Oswin Oswald called the Eleventh Doctor this when encountering him on the Dalek asylum due to his prominent chin. (TV: Asylum of the Daleks)


 * Monster: Ada Gillyflower called the Doctor her "monster", after he had been rejected by Mr Sweet's poison. She kept him alive because it was strange that he survived despite "rejection", and to have her own secret. (TV: The Crimson Horror)


 * Bow Tie: The War Doctor's nickname for the Eleventh Doctor, due to his dress sense. (PROSE: The Day of the Doctor)


 * Chinny: The Tenth Doctor's nickname for the Eleventh Doctor, due to his prominent chin. (TV: The Day of the Doctor)

Titles and epitaphs

 * Raggedy Man: A name given to the Eleventh Doctor by Amelia Pond, due to wearing the tattered remains of his predecessor's outfit. She told other people in Leadworth about the "Raggedy Doctor" and they referred to him in this way when they met him. (TV: The Eleventh Hour) Amy would call him that just before she was permanently sent to the past by a Weeping Angel. (TV: The Angels Take Manhattan) As he was about to regenerate, the Doctor hallucinated Amy telling him affectionately "Raggedy Man, good night". (TV: The Time of the Doctor)


 * A Madman with a Box: A title Amy Pond bestows on him on their first encounter after fourteen years, which he later adopted. (TV: The Eleventh Hour)


 * The Rotmeister: When he is talking to Craig Owens about the suspiciously growing rot on his ceiling, he refers to himself as the "Rotmeister" since he was an expert in rot. (TV: The Lodger)


 * Chief Executive: Alias used by the Doctor under the influence of the Entity. (COMIC: The Rise and Fall, The Other Doctor)


 * The King of Okay: A title he gave to himself when Amy was shocked to see him alive and well, having seen his older self be shot and killed at Lake Silencio. He immediately tossed the idea aside, saying it was a "rubbish title", giving Rory his own title instead. (TV: The Impossible Astronaut)


 * My Thief / My Beautiful Idiot: Names given to the Doctor by the spirit of his TARDIS during their brief time together when House took over the empty shell. (TV: The Doctor's Wife)


 * The Anti-Squid: A title the Doctor put little thought into due to the lack of preparation time. Meaning of the title is that he is the Devil of the space squid religion. (PROSE: Space Squid)


 * The Mad Monk: Called this by the public in 1207 Cumbria, although it was noted that he was "definitely not a Monk". (TV: The Bells of Saint John)


 * Clara's Boyfriend: Called this by Angie Maitland when she discovered Clara and the Doctor were time travellers (TV: The Crimson Horror) and called so by Artie Maitland upon leaving the TARDIS. (TV: Nightmare in Silver) He would later pose as Clara's Swedish boyfriend to her family. (TV: The Time of the Doctor) Shortly after regenerating, the Twelfth Doctor clarified that he was not Clara's boyfriend, though he added that "it wasn't [her] mistake". (TV: Deep Breath)


 * Number Eleven: Clara reminding him that he has not run out of regenerations. When the Doctor reminds her of "Captain Grumpy" (the War Doctor), she calls him "Number Twelve". (TV: The Time of the Doctor)


 * The Imp of the Pandorica: Among the names for the Doctor recorded by the Testimony, (TV: Twice Upon a Time) in reference to the prison in which the Eleventh Doctor was sealed. (TV: Twice Upon a Time)


 * The Beast of Trenzalore: Among the names for the Doctor recorded by the Testimony, (TV: Twice Upon a Time) in reference to the Siege of Trenzalore in which the Eleventh Doctor defended the town of Christmas. (TV: The Time of the Doctor) Also, a name used in reference to the Doctor by the Great Intelligence, though only as "the Beast". (TV: The Name of the Doctor)


 * The Demon: Kovarian taught the assassins she raised to kill the Doctor to refer to him as the Demon. The sound of his TARDIS was also referred to as "the Demon's roar". (AUDIO: The Furies)

Known uses of John Smith

 * The Twelfth Doctor introduced himself as Doctor John Smith to Michael Smith. (PROSE: Silhouette)


 * The Twelfth Doctor used the alias when going undercover as a caretaker in Coal Hill School. (TV: The Caretaker)


 * He used the German variation "Johann Schmidt" to gain Field Marshall Erwin Rommel's trust when he landed in the Sahara Desert during World War II. (COMIC: The Instruments of War)

Other aliases

 * Prisoner 428: His assumed title during his time in the Prison. (PROSE: The Blood Cell)


 * The Architect: A title used to disguise his identity when arranging to rob the Bank of Karabraxos; until the heist was almost complete, he was unable to remember this thanks to the deliberate use of a memory worm. (TV: Time Heist)


 * Dr McGuiness: An alias he assumed while investigating "the Bell" experiment in 1944, but was quickly found out and mistaken for a German spy. (PROSE: The Crawling Terror)


 * Skovox Artificer: Using a voice manipulator, the Doctor was able to convince a Skovox Blitzer that he was its superior and got it to deactivate itself. (TV: The Caretaker)


 * Doctor John Disco: At some point, the Doctor began referring to himself as Doctor Disco on answering machines. (TV: The Zygon Invasion) The Doctor later introduced himself as Dr John Disco. (TV: The Zygon Inversion, Thin Ice)


 * Doctor Funkenstein: When introducing himself to Walsh. (TV: The Zygon Invasion)


 * Basil: The Doctor jokingly said this was his real name when questioning Patronella Osgood about what her given name was, and she began referring to him as such. (TV: The Zygon Inversion)


 * Patient 89: The Doctor's number while waiting at New Hippocrates. (COMIC: The Day at the Doctors)


 * Special Agent Dan Dangerous from Scotland Yard: The Doctor made up this name when he first introduced himself to Lucy Fletcher. (TV: The Return of Doctor Mysterio)


 * Circe: Used by the Doctor while trying to infiltrate Missy's women-only social media chatroom. (PROSE: Girl Power!)


 * Doctor Robert Louis Stephenson of the Royal College of Physicians: Used while investigating the mysterious events surrounding the plague outbreak in Edinburgh in 1645. (PROSE: Plague City)

Impersonations

 * Odin: After being captured by Vikings, the Doctor tried to pass himself off as Odin to gain his freedom, but was outdone when another Odin showed up. (TV: The Girl Who Died)

Nicknames

 * Boney Rascal: A nickname given to him by Robin Hood, due to the Doctor's slim and aged appearance. (TV: Robot of Sherwood)


 * The Caretaker: Called as such by both staff and students of Coal Hill School during his brief reign as the school's caretaker. (TV: The Caretaker)


 * Outer Space Dad: Called so by Danny after he learned about the Doctor's identity; at the time, he had mistaken the Doctor for Clara's father. (TV: The Caretaker)


 * Nosferatu: Called so by corrupt cops working for Scindia-Corp, due to his aged appearance and the possibility of him being a vampiric creature that killed Tiger. (COMIC: The Swords of Kali)


 * Spindly Stick-insect: Called so by Chandra Scindia. (COMIC: The Swords of Kali)


 * The Cat in the Hat: Referred to as such by Johnny Dragotta. (COMIC: Gangland)


 * Mr. Grumpy: Referred to as such by the Tenth Doctor. (COMIC: Four Doctors)


 * Skeleton Man: A name given to him by Shona McCullough, who had mistaken him for a ghost when they first met. (TV: Last Christmas)


 * The Eyebrows: A nickname given to him by Missy to differentiate the twelfth incarnation from the other Doctors. (TV: The Witch's Familiar)


 * Me with the eyebrows: The Tenth Doctor calls him this to address him directly. (COMIC: The Lost Dimension)


 * Granddad: Nickname given by the Tenth Doctor to reference his age. (COMIC: The Lost Dimension)

Titles and epitaphs

 * The Stranger: Dubbed as such in one of Alan-a-Dale's ballads. (TV: Robot of Sherwood)


 * Mr President: Called this during by Kate Stewart and due to the Doctor being made the president of Earth during the Cyberman invasion Missy orchestrated. (TV: Death in Heaven)


 * Magician: The Twelfth Doctor has been called or referred to as a magician several times. (TV: Last Christmas, The Doctor's Meditation)


 * Ancient One: Referred to as such by the Skinks. (COMIC: Hyperballad)


 * Sawbones: A codename used to reference the Doctor for . (COMIC: Doorway to Hell)


 * The Great Destruction of the Universe: Called so by the Shadow Kin. (TV: For Tonight We Might Die)


 * Doctor Mysterio: A young Grant's name for the Doctor, if he were a comic book character, which the Doctor professed a liking to. Grant used the name again after he encountered the Doctor once more as an adult. (TV: The Return of Doctor Mysterio)

Known uses of Jane Smith

 * Sarah Jane Smith: Used in 1961 Hollywood. (PROSE: Mission of the KaaDok)
 * Jane Smith: Used in 1969 London while meeting Martha Jones. (COMIC: A Little Help from My Friends)

Other aliases

 * The Masked Assassin (PROSE: The Death List)
 * Good Nurse: Name given to her on Lobos by Graham O'Brien to fit with the local religion. (PROSE: The Good Doctor)
 * The Curator: Used while working at a museum in Venice. (PROSE: The Liar, the Glitch and the War Zone)
 * Rose: Used in 1900s Bern. (PROSE: Einstein and the Doctor)
 * The Marvelous Apparating Lady: Used in 1834 London during an inventor's auction, though she first tried "The Marvelous Apparating Man" out of habit. (TV: Spyfall)

Nicknames

 * Doc: Used by her companion Graham O'Brien. (TV: Rosa et al.)

Other aliases

 * Ruth Clayton: A human identity assumed by a previously unknown incarnation of the Doctor while she was hiding out on Earth, as a fugitive from Gallifrey. This version of the Doctor used the Chameleon Arch in her TARDIS to temporarily transform herself into a human named Ruth. (TV: Fugitive of the Judoon)
 * Zachary: The Doctor's codename among the UNIT troops. (PROSE: The Shadows of Avalon)

Nicknames

 * Damsel: A codename for the Doctor that River Song used on her missions, owing to the fact that he "needed rescuing a lot" of the time. (TV: The Husbands of River Song)

Titles and epitaphs

 * The Idiot Child: A name for the Doctor used by Ohila. (PROSE: The Day of the Doctor)


 * High Earl of the Imperial House: The Doctor's title as a Draconian nobleman. (PROSE: Catastrophea)


 * The Zonewalker (PROSE: Crimson Dawn)


 * The Shadow-thief (PROSE: Crimson Dawn)


 * The Trickster of Time (PROSE: Crimson Dawn)


 * Belot'ssar: A title used by the Ice Warriors to refer to the Doctor. The name means "cold blue star" in reference to either the light on top of the TARDIS or the cold blue star he showed them to settle near after Mars became uninhabitable. The name was given to him by Lord Azylax. (PROSE: The Silent Stars Go By)


 * The Vessel of The Final Darkness: Another title in reference to the Doctor by the Great Intelligence. (TV: The Name of the Doctor)


 * Bringer of Darkness: Used by the Tenth Doctor while facing a rabbit, which he thought was a Zygon. (TV: The Day of the Doctor) Captain van Volk referred to the Twelfth Doctor as "Doctor Bringer-of-Darkness", (COMIC: The Fractures) and the Twelfth Doctor later referred to himself with the epitah. (COMIC: Invasion of the Mindmorphs)


 * The Roaring Winds of Righteousness: A title coined by Petronella Osgood, which the Twelfth Doctor critisised for being "a little too flatulent". (COMIC: Robo Rampage)


 * The Shadow of the Valeyard: Among the names for the Doctor recorded by the Testimony. (TV: Twice Upon a Time)


 * The Last Tree of Garsennon: Among the names for the Doctor recorded by the Testimony. (TV: Twice Upon a Time)


 * The Uniter of the Thirteen Worlds of the Hoomis Collective (COMIC: Midnight Feast)
 * The Smiter of the Frangian Simulacra (COMIC: Midnight Feast)
 * The Aathkeeper of Valnis (COMIC: Midnight Feast)
 * The Mighty Lord of TAR-DIS (COMIC: Midnight Feast)

Other

 * The Timeless Child: The original name given to the Doctor in their earliest known history due to their ability to regenerate indefinitely. (TV: The Timeless Children)


 * The Valeyard: A version of the Doctor created sometime between his twelfth and final incarnations. (TV: The Ultimate Foe, The Name of the Doctor)

The Doctor's name

 * The first edition of the behind-the-scenes book The Making of Doctor Who, published in 1972, stated that the Doctor's name was "∂³∑x²". It was later spelt as "d³ᓬx²" in the "Who is the Doctor" prologue of Marvel Premiere #57 in 1980. This has never been confirmed in any Doctor Who narrative, but these letters do appear on the plinth in the Tomb of Rassilon in The Five Doctors. They are also seen on K9's regeneration unit in Regeneration.
 * The same first edition explained the Doctor "is never cowardly" which was expanded in the second edition to "never cruel or cowardly" and that "he never gives in, and he never gives up." These phrases were later used in the TV series as the promise the Doctor made when choosing his name.
 * Executive producer Steven Moffat jokingly said that no one can know the Doctor's name, except each successive showrunner. "We're commanded never to reveal what we have learned because then the show would have to be renamed Mildred. Oh, bugger."

Ordinal or cardinal
In The ArcHive Tapes, the narrator refers to the different incarnations of the Doctor as "Doctor (cardinal number)" rather than "the (ordinal number) Doctor".