Jack

 has several meanings pertinent to the Doctor Who universe and the real world. They are listed below in alphabetical order by surname. If no surname is available, alphabetization occurs by the disambiguation term — that is, the bit between the parentheses in a title like Waitress (Random Shoes).

As only name

 * Big Jack (PROSE: Snowfall)
 * Jack (Cat's Cradle: Witch Mark) (PROSE: Cat's Cradle: Witch Mark)
 * Jack (Circular Time) (AUDIO: Circular Time)
 * Jack (Paradise Frost) (AUDIO: Paradise Frost)
 * Jack (Penny Wise, Pound Foolish) (AUDIO: Penny Wise, Pound Foolish)
 * Jack (Pitter-Patter) (PROSE: Pitter-Patter)
 * Jack (Snow Blind) (AUDIO: Snow Blind)
 * Jack the Ripper (TV: The Talons of Weng-Chiang, et al)
 * Jack (Warlock) (PROSE: Warlock, Warchild)
 * Spring-heeled Jack (COMIC: The Curious Tale of Spring-Heeled Jack)

As first name

 * Jack Bartlett (PROSE: Bad Therapy)
 * Jack Blood (PROSE: Cat's Cradle: Warhead)
 * Jack Canning (PROSE: The Touch of the Nurazh)
 * Jack Chance (PROSE: Mission: Impractical)
 * Jack Cooper (PROSE: Amorality Tale)
 * Jack Corrigan (Conundrum) (PROSE: Conundrum)
 * Jack Corrigan (Destination: Nerva) (AUDIO: Destination: Nerva)
 * Jack Coulson (AUDIO: Energy of the Daleks)
 * Jack Craddock (TV: The Dalek Invasion of Earth)
 * Jack Dempsey (PROSE: Timewyrm: Genesys)
 * Jack Devitt (PROSE: Eye of Heaven)
 * Jack Dupre (PROSE: The City of the Dead)
 * Jack Finney (PROSE: First Frontier)
 * Jack Michael Forrester (PROSE: Second Chances)
 * Captain Jack Harkaway (TV: The Mind Robber)
 * Jack Harkness, a 51st century con artist who travelled with the Doctor. (TV: The Empty Child)
 * Jack Harkness (Captain Jack Harkness) (TV: Captain Jack Harkness)
 * Jack Harris (PROSE: The Eight Doctors)
 * Jack Hobson (TV: The Moonbase)
 * Jack Howe (PROSE: The Bodysnatchers)
 * Jack Kowaczski (PROSE: The Last Resort)
 * Jack Michaels (PROSE: Option Lock
 * Jack Pilgrim (PROSE: Cat's Cradle: Witch Mark)
 * Jack Prudhoe (PROSE: Nightshade)
 * Jack Ruby (PROSE: Untitled (DWM 171))
 * Jack Strong (PROSE: The Devil-Birds of Corbo, The Playthings of Fo)
 * Jack Tracy (TV: The Invasion, PROSE: The Scales of Injustice)
 * Jack Tyler (TV: Image of the Fendahl)
 * Jack Ward (TV: The Mark of the Rani)
 * Jack Ianto Geraint Williams (PROSE: The Twilight Streets)

Guest

 * Jack Bligh, who played Gaptooth in TV: The Smugglers
 * Jack Cunningham, who played the jailer in TV: The Reign of Terror
 * Jack Edwards, who played a dancer in TV: The Masque of Mandragora
 * Jack Galloway, who played Joseph Willow in TV: The Awakening
 * Jack May, who played Nikolai Hermack in TV: The Space Pirates
 * Jack Melford, who played Menelaus in TV: The Myth Makers
 * Jack Montgomery, who played young Jack Harkness in TV: Adam
 * Jack Tarlton, who played Tom Hitchinson in TV: Aliens of London / World War Three
 * Jack Tarran, who played the 1st guard in TV: The Massacre of St Bartholomew's Eve
 * Jack Watling, who played Edward Travers in TV: The Abominable Snowmen
 * Jack Woolgar, who played Staff Sgt Arnold in TV: The Web of Fear

Monster specialists

 * Jack Pitt, who played various monsters in Doctor Who

Vocal

 * Jack Brown, who played a pilot in AUDIO: Deimos and The Resurrection of Mars
 * Jack Galagher, who voiced various characters for Big Finish Productions

As surname

 * Stephen Jack, who played John Farrel in TV: Terror of the Autons

Designers

 * Jack Robinson, who was designer for TV: The Underwater Menace

Sound design, effects, music

 * Jack Brummitt, who provided studio sound for several Doctor Who stories
 * Jack Clayton, who provided studio sound for TV: An Unearthly Child and The Daleks

Visual effects

 * Jack Kine, who was visual effects designer for TV: The Mind Robber

Other

 * Jack Able, who proofread various issues of Doctor Who (1984)