No one usually known as "Doc" (so no Samson or Savage) and no one who's just "The Doctor".
- Doctor Adrian (Adrian Myles)
- Doctor Alchemy (Albert Desmond)
- Doctor Arcane (Clinton Avery)
- Doctor Beat (McDowell)
- Doctor Bedlam
- Doctor Bong (Lester Verde)
- Doctor Brawn
- Doctor Chaos
- Doctor Claw
- Doctor Clownius
- Doctor Colossus The Simpsons
- Doctor Crab
- Doctor Cyber
- Doctor Darkness (Doctor Cambridge)
- Doctor Death (Karl Hellfern)
- Doctor Decibel (Anton Decibel)
- Doctor Demonicus (Douglas Birely)
- Doctor Deseret (Denholm)
- Doctor Destiny
- Doctor Diamond (Drake Gordon)
- Doctor Diehard
- Doctor Dome
- Doctor Doom (Victor Von Doom)
- Doctor Doomsday (Victor Von Doom)
- Doctor Dorcas (Lemuel Dorcas)
- Doctor Double X
- Doctor Draino
- Doctor Droll
- Doctor Druid (Anthony Druid)
- Doctor Eclipse (Fred Bender)
- Doctor Eggman (Ivo Robotnik)
- Doctor Event Horizon Man (Jack Turner)
- Doctor Evil I “Captain Action”
- Doctor Evil II (Douglas Powers)
- Doctor Fang
- Doctor Fate I (Kent Nelson)
- Doctor Fate II (Linda Strauss)
- Doctor Fate III (Khalid Ben-Hassan)
- Doctor Faustus (Johann Fennhoff)
- Doctor Fear (Liam Wilderman)
- Doctor Frost
- Doctor Fu Manchu
- Doctor Future
- Doctor Gargunza (Emil Gargunza)
- Doctor Gearbox (Anton Girbachs)
- Doctor Genus One-Punch Man
- Doctor Girlfriend
- Doctor Glitternight
- Doctor Gratz
- Doctor Hastor (Anton Hastor)
- Doctor Horus
- Doctor Hydro (Herman Frayne)
- Doctor Hypno Centaur Publications
- Doctor Ice
- Doctor Impossible
- Doctor Light I (“All-American Comics”
- Doctor Light II (Arthur Light)
- Doctor Light III (Kimiyo Hoshi)
- Doctor Manhattan (Jon Osterman)
- Doctor Meggido
- Doctor Mensana
- Doctor Mesmer
- Doctor Midnight (Beth Chapel)
- Doctor Mid-Nite I (Charles McNider)
- Doctor Mid-Nite II (Pieter Cross)
- Doctor Minerva (Minn-Erva)
- Doctor Mirage (Hwen Fong)
- Doctor Mist (Nommo)
- Doctor Moon
- Doctor Morg
- Doctor Mortis
- Doctor Multiverse (Maya Chamara)
- Doctor Mysterioso
- Doctor Mystic Centaur Publications
- Doctor Nemesis I (James Bradley)
- Doctor Nemesis II (Mason Grimshaw)
- Doctor Nightshade (Tilda Johnson)
- Doctor Nikola
- Doctor No (Julius No)
- Doctor No-Face (Bart Magan)
- Doctor Occult (Richard Occult)
- Doctor Octopus I (Otto Octavius)
- Doctor Octopus II (Carolyn Trainer)
- Doctor Odd
- Doctor Permafrost
- Doctor Phosphorus (Alex Sartorius)
- Doctor Poison
- Doctor Polaris (Neal Emerson)
- Doctor Psycho
- Doctor Radius
- Doctor Regulus (Zaxton Regulus)
- Doctor Rune (Anthony Rune)
- Doctor Sax (Jack Dulouz)
- Doctor Shrinker
- Doctor Sin “IPC”
- Doctor Sivana (Thadeus Bodog Sivana)
- Doctor Solar (Philip Solar)
- Doctor Spectro (Tom Emery)
- Doctor Spectrum (Joseph Ledger)
- Doctor Star (James Robinson
- Doctor Stellar (Peter Starr)
- Doctor Strange I (Carlo Strange)
- Doctor Strange II (Stephen Strange)
- Doctor Strange III (Clea Strange)
- Doctor Strangefate (Charles Xavier)
- Doctor Stratos (Constantine Stratos)
- Doctor Sun
- Doctor Synne
- Doctor Synthe Centaur Publications
- Doctor Tachyon (Tisianne)
- Doctor Tamaro
- Doctor Tome
- Doctor Tomorrow (Bart Simms)
- Doctor Tzin-Tzin
- Doctor Vampire (John Rogers)
- Doctor Vault (Aloysius Vault)
- Doctor Villain (Arthur Villain)
- Doctor Voodoo I “Doll Man”
- Doctor Voodoo II (Jericho Drumm)
- Doctor Voodoo III “Detective Comics”
- Doctor Weird (Rex Ward)
- Doctor X
- Doctor Xadu (Xa-Du)
- Doctor Zeus
- Doctor Zodiac (Theodore Carrigan)
- Doctor Zroa (Reuben Bachar)
- Doktor Nemir (Marko Nemir)
Replies
Doctor Regulus, Legion of Super-Heroes foe
Doctor Glitternight, Werewolf By Night foe
Doctor Xadu, Phantom Zone prisoner
Doctor Light (Golden Age), enemy of Doctor Mid-Nite
Doctor Adrian, foe of the Atom (Action Comics #438)
Doctor Brawn, fought Batgirl & Robin (Batman Family #14)
Doctor Dome, archenemy of Plastic Man (mid-60s)
Doctor Fang, foe of Batman (mid-80s)
Doctor Horus, fought Superman and Batgirl (DC Comics Presents #19)
Doctor Mist, mentor of the Global Guardians
Doctor Moon, evil scientist, fought Wonder Woman and Batman separately
Doctor No-Face opposed Batman in the 50s
Doctor Tzin-Tzin, illusionist who fought Batman
Doctor Voodoo I, enemy of Batgirl
Doctor Voodoo II, formerly Brother Voodoo
Doctor Zodiac, battled Superman & Batman
Added these four, plus Doctor Nightshade.
Philip Portelli said:
Doctor Decibel, fought the Squadron Supreme
Doctor Dorcas, fought the Sub-Mariner
Doctor Evil, fought Captain Action or Austin Powers, whichever you meant
Doctor Hydro, battled the Sub-Mariner
Doctor Minerva, Kree scientist who fought Captain Mar-Vell and Quasar
Doctor Sax, fought the Dazzler
Doctor Strange, fought Iron Man in Tales of Suspense #41
Doctor Vault, archenemy of It, the Living Colossus
Doctor Star (Dr James Robinson). (reprinted as Doctor Andromeda) from Black Hammer universe.
Thanks, folks! Added the following:
Added Doctor Stratos.
Doctor Shrinker, Saturday Morning live-action villain
Added.
Philip Portelli said:
Valiant has a Doctor Tomorrow.