You Are Number Six/Live-Action TV

"They've given you a number And taken away your name."
 * The Cylons from the 2004 Battlestar Galactica remake, especially Six. Most of the others were originally introduced as if they were human, giving them a name in addition to their model number. Ronald D. Moore has confirmed Six as another nod to The Prisoner. One version of six is nicknamed "Caprica" by other Cylons, however—she was the Number Six that went to Caprica to lay the ground-work of the destruction of the Colonies. Thus, "Caprica Six".
 * On the subject of Cylons and Caprica, one wonders whether Daniel Graystone would continue to call the robot U-87 if he knew that Zoe was actually in there.
 * Six LeMeure from Blossom. According to her parents, that was how many beers it took to conceive her.
 * In Buffy the Vampire Slayer, the Initiative refer to Spike as "Hostile 17".
 * In Dark Angel, all of the transgenics have designations, except Joshua (the first) and his brother Isaac.
 * The first part of the designation denotes their series, the second part denotes their number in the series. Max is X5-452, so 452th in the X5 series. Zack is X5-599. Alec is X5-494, and his twin Ben is X5-493.
 * The DRD 1812 in the science fiction series Farscape is a subversion. The DRDs in general have no names or independent identities, so anything that sets them apart actually serves to humanize them. 1812 is named for Tchaikovsky's "1812 Overture", which it sometimes plays, and it is further identified by its unique red, white, and blue paint job.
 * Most of the agents from Get Smart, including "Agent 99" who otherwise has No Name Given. Maxwell Smart's number is 86. The choice of numbers is an intentional hint that, though Max outranks 99, she is the more competent agent. There's also the perpetually unlucky 13 who is never given a name.
 * Dr. Yang of Grey's Anatomy generally refers to her interns by number.
 * "Thirteen" from House has a name, but Dr. House never calls her by anything but her number from when she was merely a job applicant. For her part, she's fine with it.
 * Even her boyfriend calls her "Thirteen", though, to be fair, she calls him "Foreman."
 * And at one point, they're even called "Foreteen."
 * The protagonist of Kyle XY spent sixteen years or so of his life as Subject 781227.
 * In an episode of Malcolm in the Middle, Malcolm's new teacher addresses all the students in the gifted class by a number corresponding to their rank according to grades. It works well enough that one of them even forgets his real name.
 * In a particularly scarring episode of Are You Afraid of the Dark? a witch steals the faces of girls to stay young and beautiful. After she does, and leaves the girls with horrifying blank faces, they're assigned numbers and forced to work for her.
 * That particular episode has some probably accidental but still rather queasy parallels to human trafficking.
 * Seven, the Cousin Oliver from Married... with Children.
 * Dillon of Power Rangers RPM is still called "D44" by Venjix and his minions. To shed some light, Dillion had lost his memories after being one of several test subjects (at least 44 times 4 if the D is any indication) in a Venjix project to implant his tech inside humans.
 * Subverted in Choudenshi Bioman, in which while each of the Biomen has their own names, their codenames are represented by their color and number in the roll call: Red One (Shiro), Green Two (Shingo), Blue Three (Ryuta), Yellow Four (Mika, then Jun) and Pink Five (Hikaru).
 * A common theme in The Prisoner, and Trope Namer. Made more interesting in that
 * "Who is Number One?" See how it works?
 * Given a Shout-Out in the Prisoner-esque Nowhere Man when Veil infiltrates a paranoid militia and is renamed Number Six.
 * If you believe the theory that John Drake is Number Six, the famous theme song for Danger Man/Secret Agent becomes either Hilarious in Hindsight or Harsher in Hindsight:

"VAL: What is your name? You: This Troper. VAL: That is incorrect. The number on your pod is now your name. What is your name? You: My name is Number Six."
 * In Seinfeld, George suggested the name "Seven" for a baby. A couple in the episode ended up using it.
 * The Fox Reality original series Solitary starts this way...


 * An episode of Space Cases had a prisoner switching her place with a female "crew" member. In the prison, she was only addressed as "Prisoner 24601".
 * The replicator "Fifth" from Stargate SG-1, as well as the other human-form replicators.
 * Seven of Nine from Star Trek: Voyager. Her name (before she was assimilated as a child) was Annika Hansen. When she was later freed from the Collective by Captain Janeway, the latter suggested replacing her Borg designation (Seven of Nine, Tertiary Adjunct of Unimatrix Zero One) with her human name. Seven of Nine refuses, as she's not happy about "becoming human" in the first place, so they compromise on "Seven of Nine". An interesting example of someone asserting their individuality via this trope (though you could say Seven was deliberately "dehumanizing" herself).
 * Most Borg are designated as such. Hugh was originally known as Third of Five before the Enterprise crew renamed him. And in Voyager, there are passing references made to the designation of other Borg (usually by the Borg Queen).
 * The Borg also designate alien species by code numbers. Humans are "Species 5618", Klingons are "Species 5008", Vulcans are "Species 3259" and so on. One very dangerous alien species encountered in Voyager is referred to as "Species 8472" because there is no other known name for them.
 * And Number One from the pilot episode "The Cage" and reused footage in the two-parter "The Menagerie".
 * That's because she was the ship's XO, it wasn't her name (as confirmed in Star Trek: Discovery). Note that Riker was also called "Number One" on occasion by Picard in TNG.
 * In Timeslip, Simon discovers that his future self is known only as "Controller 2957". The others who work for the technocracy, mostly clones, also are known only by numbers.
 * In The West Wing, Will gives the speech writing interns (three of whom are named Lauren) numbered jerseys to help identify them.
 * The X-Files episode "Eve" features a series of clones of the same woman, all denoting themselves as Eve # according to the order they were cloned. Eve 6 of this episode mentions biting a guard in the eye. Due to this, one of the band members of Eve 6 decided to use that as their band name.
 * Kryten 2X4B 523P in Red Dwarf. He thinks 2X4B is a jerky middle name, but it's not as bad as 2Q4B.
 * Doctor Who:
 * The episode "The Eleventh Hour" features a.
 * In-universe it has also been established that the Doctor's nickname on Gallifrey (not his name; his name is secret) was 'Theta Sigma', which isn't actually numbers but carries a similar tone.
 * Another example is the Ood, which have no names but are referred to by a numerical designation such as "Ood 1-alpha-1".
 * On The Dating Game, a contestant's potential choices would be referred to as "Bachelor #__" rather than by name.
 * The Outer Limits episode "The Camp" featured humans used as slave labor by aliens. The protagonist is called "Prisoner 98843".
 * The episode "Children of Methuselah" of the legendarily bad TV series The Starlost featured a "training bridge" for the Earthship ARK which was staffed entirely by immortal children known only by numbers, not names.
 * In an episode of The Adventures of Superman, the cast meets an exiled Martian whose people use number rather than names; this one's number is Zero Zero Zero Minus One (overlapping with Unfortunate Name, it seems). They call him "Mr. Zero" for short.