Like the Doctor, the renegade Time Lord known as the Master used many aliases. However, while the Doctor used false names on a fairly ad hoc basis to avoid awkward questions, the Master usually adopted them in order to further whatever scheme he was currently embarked upon.
| Alias | When used | Story | Etymology |
|---|---|---|---|
| Colonel Masters | to infiltrate Rex Farrel's plastics company | Terror of the Autons | |
| Reverend Magister | to insinuate himself socially into the Devil's End community | The Dæmons | Latin for master |
| Professor Thascalos | to gain access to facilities of the Newton Institute | The Time Monster | Greek for master, pointed out by Jo Grant |
| Duke Dominus | to impersonate a 1930s Chicago gangster | The Duke of Dominoes | |
| Emil Keller | assumed identity of the creator of the Keller Machine | The Mind of Evil | Emil is derived from the Latin word aemulus, meaning rival, and Keller is derived from Old English cwellere, meaning executioner |
| Martin Jurgens | while posing as an Adjudicator | Colony in Space |
Anagram of Master Gunnjir (gunnjir is the spear of Odin, head of the Norse pantheon) |
| Frey | whilst in Sweden, 141 | The Spear of Destiny | Old Norse for master |
| Mwalimu | while hiding beneath Colonel Spindleton's manor house in 1979 | Trail of the White Worm | Swahili for master in the sense of teacher |
| Estro | while posing as an adviser to Lord Haldoran in an effort to procure a Dalek matter-transmuter | Legacy of the Daleks | Esperanto for master |
| Gospodar | to access the TITAN Array in order to destroy the Chronovores | The Quantum Archangel | Serbian, Croatian and Slovenian for master |
| Mr Seta | Used aboard the starship Gallery | Dust Breeding | anagram of master |
| The Portreeve | to trap the Fifth Doctor in Castrovalva | Castrovalva | |
| Kalid | used to take control of the Xeraphin gestalt | Time-Flight | As Kalid, he affected the identity of a vaguely Arabian sorcerer. Kalid derives from the Indian Kalidasa meaning servant of Kali, an Indian goddess of time and change and usually depicted as being dark and violent. |
| Sir Gilles Estram | to avert the signing of the Magna Carta in 1215. | The King's Demons | Estram is a simple anagram. |
| The Sheriff | to gain access to the regenerative fountain near Eternity. | A Town Called Eternity | |
| Major Kreer | used when allied with the Tzun in 1950s America. | First Frontier | |
| Template:Frontier | Housewarming | ||
| Dr John Smith | Used while amnesiac on an unnamed colony world | Master | |
| Bruce | occasionally reverted to impersonation of a San Franciscan paramedic named Bruce after he had taken over Bruce's body | Doctor Who | |
| Professor Yana | chameleon arch identity | Utopia | Had no known meaning of its own, but the Face of Boe made up an acronym, "You Are Not Alone" |
| Harold Saxon | used to win Prime Ministership of the United Kingdom | Love & Monsters and several other stories | Mister Saxon was an anagram of Master No Six; Harold is a derivative of Old English Hereweald meaning Master of the Armies |
Behind the scenes
- During Anthony Ainley's tenure as the Master, pseudonyms made from anagrams of 'Tony Ainley' were often used in the credits — both on-screen and in Radio Times — for the Master's disguises, such as Neil Toynay for the Portreeve in TV: Castrovalva.
- Another, craftier pseudonym was used in Radio Times for TV: The King's Demons, when Sir Gilles was listed as being played by 'James Stoker' — an anagram of 'Master's Joke'.