Colin

 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

 * Colin (Everything Changes) (TW: Everything Changes)

As first name

 * Colin Acres Junior (TM: Mrs Acres)
 * Colin Davies (TW: Something Borrowed, TWN: Pack Animals)
 * Colin Dove (BBV: The Zero Imperative)
 * Colin Farrell (BFA: The Gathering)
 * Colin Frazer (DW: Arc of Infinity)
 * Fudge Higgins, also known as Colin Higgins (DWM: Doctor Who and the Star Beast, DWY: Star Beast II)
 * Colin Maloney (TW: The Categories of Life, The Middle Men)
 * Colin McConnon (NSA: Wetworld)
 * Colin McLaren (DW: The Highlanders)
 * Colin Redmayne (DW: The Enemy of the World)
 * Colin Skinner (DW: Love & Monsters)
 * Colin Thackeray (DW: The Seeds of Doom)

Regular

 * Colin Baker, who played the Sixth Doctor as well as other smaller roles

Guest

 * Colin Baxter, who played a policeman in TW: Meat
 * Colin Bell, who played C.P.O. Summers in DW: The Sea Devils and Private Bryson in DW: Invasion of the Dinosaurs
 * Colin Douglas, who played Donald Bruce in DW: The Enemy of the World and Reuben in DW: Horror of Fang Rock
 * Colin Fay, who played Condo in DW: The Brain of Morbius
 * Colin Gordon, who played the Commandant in DW: The Faceless Ones
 * Colin Jeavons, who played Damon in DW: The Underwater Menace and George Tracey in KAC: A Girl's Best Friend
 * Colin McCormack, who played the Commander in DW: The Sun Makers
 * Colin McFarlane, who played General Austin Pierce in TW: Children of Earth: Day One, Day Three and Day Five and voiced the Heavenly Host in DW: Voyage of the Damned
 * Colin Miller, who played Harry Sline in SP: The Curse of the Daleks
 * Colin Morgan, who played Jethro Cane in DW: Midnight
 * Colin Prockter, who played the Head Chef in DW: The Long Game and the Air Raid Warden in DW: Victory of the Daleks''
 * Colin Salmon, who played Doctor Moon in DW: Silence in the Library / Forest of the Dead and voiced Salway in BFA: Wirrn Dawn
 * Colin Spaull, who played various television and audio roles for Doctor Who and Big Finish Productions
 * Colin Stinton, who played Arthur Coleman Winters in DW: The Sound of Drums
 * Colin Thomas, who played Sole in DW: The Face of Evil
 * Colin Warman, who played a Robot Yeti in DW: The Web of Fear

Vocal

 * Colin McIntyre, who did voice work for Big Finish Productions

Vocal

 * Pandora Colin, who voiced Fash in BFA: Prisoner of the Sun

Designers

 * Colin Green, who was designer for DW: Death to the Daleks and Enlightenment
 * Colin Shaw, who was designer for DW: The Moonbase

Directors

 * Colin Teague, who was a director for Doctor Who, Torchwood and The Sarah Jane Adventures

Lighting

 * Colin McCarthy, who was gaffer for The Curse of Fatal Death
 * Colin Powton, who was best boy for SJA: Invasion of the Bane

Sound design, effects, music

 * Colin Dixon, who provided special sounds for Doctor Who

Visual effects

 * Colin Mapson, who was a visual effects designer for Doctor Who

Other

 * Colin Dudley, who was production assistant for DW: The Sea Devils and The Invasion of Time
 * Colin Eggleston, who was film editor for DW: The Smugglers
 * Colin Hobson, who was a film editor for Doctor Who
 * Colin Lavers, who did costumes for DW: The Power of Kroll, Four to Doomsday, The King's Demons and The Five Doctors
 * Colin Leslie, who was production assistant for DW: The Chase

Prose

 * Colin Harvey, who wrote ST: The Eyes Have It and But Once a Year
 * Colin Varney, who wrote BE: Toy

Comics

 * Colin Andrew, who was a penciller and inker for DWM: Pureblood, Final Genesis, Victims and Food for Thought and DWMS: Are You Listening and Younger and Wiser
 * Colin Howard, who was a penciller and inker for Doctor Who Magazine and Doctor Who Classic Comics

Other

 * Colin Brake, who wrote various prose and audio stories