Institutional Apparel

"Who the devil are these guys? The Planaria Gang? Half the city's Municipal Elevator Operators having a club meeting? Those are prison uniforms. Not a wise idea; if they escaped, people would look over their heads, and be unable to give a good description. I -- I can't say! I saw his face for a second, but then my eyes were unaccountably drawn upwards."

- James Lileks (on the prison garb with upward-pointing arrows featured in Dressed to Kill)

There are a handful of outfits used to identify when a character has been placed in some manner of corrective institution, such as a mental hospital or prison. In the case of both, this trope is usually somewhat justified, because people from prisons or mental hospitals are people who need to stand out from the normal population if they haven't been rehabilitated or declared sane. Unless it's a comic strip or a cartoon with Limited Animation, the trope is, of a necessity, temporary. Crazy people and prisoners who don't want to go back to where they broke out from make it an immediate priority to find clothes that will let them blend in.

For prisoners:
 * Old school: Black and white horizontal stripes, either a jumpsuit or shirt and trousers with matching pillbox hat.
 * Ball and chain manacles either on each prisoner, or they're all chained to each other by the ankles.
 * New school: Frequently, bright orange jumpsuits with white undershirts, though jumpsuits of less obvious colors are also used.
 * Grey jumpsuits with reflective vests for when they're forced to do the road work as part of their sentence.
 * In the United Kingdom and the (former) colonies, the old uniform used to be black arrows on a white shirt and trousers, sometimes with the pillbox hat.
 * The reason for this is that, back in The Middle Ages, all items purchased on behalf of the crown (what we'd now call "Government property") were stamped with a broad arrow. This included the fabric for prison uniforms.
 * Russian prisoners color-code their prison uniforms, that are originally either dark gray or blue. The Mafiya members dye their uniforms black; the common unlucky petty criminals wear dark blue, and the chushoks, the pariahs who are bullied and forced to do every bit of the dirty work, and the petukhs, who are raped, wear dirty gray. This is usually done in forced labor camps, where dyes, needles and thread to customize the uniforms are obtainable, and the prison guards do not object.
 * Truth in Television in the US, as jumpsuit color denotes severity of crime.

For insane asylums or mental hospitals:
 * Whatever outfit the inmate is wearing with a straitjacket on top. The strait jacket may be partly undone.
 * Scrubs in some neutral color.
 * Rags based on the inmate's original outfit.
 * Belts, drawstrings, shoelaces and/or anything else the patient could use as a weapon to harm self or others has been removed.

Advertising

 * McDonald's mascot Hamburgler wears the horizontal stripes.

Anime & Manga

 * Magical Girl Lyrical Nanoha has all those thrown into prisons and corrective facilities wearing white shirts, trousers and shoes during their stay.

Comics -- Books

 * The "old school" arrow variant of the uniform still appears in British children's comics.
 * During the early Silver Age, Lex Luthor's "costume" was his prison greys, showing that he hadn't even bothered to change his clothes before starting his latest evil scheme (and considering he usually ended up back in prison by the end of any given story, it might be taken as a subconscious admittance of defeat). At some point, it was stated that he wore his prison uniform to remind himself how much he hated Superman for putting him in prison.
 * The Beagle Boys have prison stripes and prison numbers on their chests (they don't have names, only prison numbers). They also have shaved heads and masks covering their eyes, but that just shows they're criminals.
 * The Beagle Boys from works involving Scrooge McDuck (e.g. comic books and DuckTales) wear long-sleeved orange tops and blue jeans. Ma Beagle wears an orange jacket over a white blouse, and a blue skirt.
 * Watchmen had charcoal-grey prison uniforms, possibly as one of those slight differences (like everyone wearing double-breasted suits) to indicate its Alternate History.
 * The Justice Society of America fought a time-traveling villain, Knodar, who billed himself as "the last criminal" -- he wore a custom-designed prison uniform, as there were no other prisoners in his time period; indeed, they had to reinvent jail just for him. For the record, it was a gray, form-fitting bodysuit with the letter "P" for "prisoner" all over it in black lettering.
 * Prisoners in Judge Dredd wear a variant on the horizontal stripes.
 * Lucky Luke: The Daltons, since they are constantly trying (and succeeding) to break out of prison, spend much of their time in black-and-yellow striped outfits.
 * In All Fall Down, wear this after they end up in prison.

Films -- Live-Action

 * The convicts in the prison in Johnny Dangerously wear the horizontal stripes.
 * The Dark Knight has criminals in orange jumpsuits.
 * Con Air has criminals in jumpsuits of some other colour. The prisoners are Color Coded for Your Convenience: normal inmates get Blue, the really scary ones get Orange, and the pants-wettingly scary Steve Buscemi gets White.
 * Hancock and the other convicts in the Los Angeles prison wore the orange jumpsuit.
 * O Brother, Where Art Thou?? had the old school striped prison outfits. Justified in that if anywhere would have striped jumpsuits for prisoners, it's 1930s Mississippi.
 * In the movie The Quick and the Dead, Scars is still wearing his striped prison uniform, having just broken out of prison and come straight to the quick-draw competition.
 * The Fugitive does the orange jumpsuit; Dr. Kimble's first challenge after escaping is to steal some less conspicuous clothing.
 * In the Harry Potter movies, Azkaban prisoners wear the stripes. Sirius has a shirt and trousers, and Bellatrix has what look like a striped hospital gown.
 * In Batman and Robin, Mr. Freeze wears the old-school prison stripes uniform, which fits in perfectly with the campiness of the rest of the film.
 * A major plot in The Hurricane. Ruben Carter refused to wear prison stripes, and stayed in "the hole" for weeks as a result. Finally the head guard let him wear prison pajamas without stripes on them.
 * In the Firefly film Serenity, in the intro showing River's time at the Academy, she is shown wearing a form-fitting gray outfit that is like the bastard child of a prisoner uniform and a hospital gown, at least aesthetically.
 * In The Chronicles of Riddick: Escape from Butcher Bay, the prisoners usually wear orange jumpsuits with grey patches sewn onto the elbows and knees, or short-sleeved variants thereof. Riddick himself wears the trousers of this jumpsuit and a black tank top.
 * Whenever The Three Stooges were in prison they'd be wearing the old school striped uniforms.

Literature

 * The Stainless Steel Rat. The Grey Men put their prisoners in a transparent plastic outfit to prevent them hiding anything.
 * In the short story "Good Friends and Good Family" (scroll down) by Desmond Warzel, the viewpoint character, a county jail inmate, decries the uncomfortable nature of the orange scrubs and the poor fit of the jail-issue sandals.

Live-Action TV

 * The arrow variation uniform can be seen in The Goodies episode "Goodies in the Nick."
 * In Prison Break the convicts have blue fatigues. At one point of the titular escape,.
 * The general issue fatigues in Oz are grey with the prisoner's number on them. The prisoners in Emerald City get to wear civvies.
 * When Ned was Mistaken for Murderer on Pushing Daisies, he wore an orange jumpsuit in prison.
 * Rebus puzzles on Concentration used this trope to represent the syllable "con".
 * In The Sarah Connor Chronicles, the long-term human prisoners of Skynet wear ill-fitting, drab, dirty gray-white uniforms.
 * At least once on Myth Busters the cast has worn the striped version while testing prison-based myths.
 * Misfits is all over this trope.
 * Sketches taking place in prison on The Benny Hill Show have the British arrow-covered uniforms. Some gags are milked out of it, such as Benny standing in a line with other inmates, whose arrows, both on the right and the left, all point toward him, while the arrows of his own uniform point upwards, toward his face.

Music

 * The Johnny Cash song "I Got Stripes" is a reference to the old-school striped uniforms.

Pro Wrestling

 * Kevin Wacholz wrestled in orange prison scrubs during his brief WWE stint as "Nailz" and his single WCW match as "The Prisoner".
 * Rey Mysterio, Jr. sometimes wore orange prison gear during that portion of his WCW career in which he was unmasked.
 * There was also a rather large N.W.A. jobber who wore prison clothes and was known simply as "Death Row".

Theater

 * The female prisoners in Chicago wore drab greys, with fancies underneath. For their numbers, they wore typical performance outfits, but that was a conceit of the format in which the story was told.

Toys

 * LEGO police sets, starting in 1993, occasionally included a prisoner figure with a white striped shirt and black pants. This switched over to orange jumpsuits in the "World City" line, and then back to stripes since 2005.

Video Games

 * In Street Fighter Alpha 3, Cody, a recently escaped convict, has the horizontal stripes. In the next-gen sequel to Final Fight, he's apparently been recaptured and re-escaped, since he has the orange scrubs instead. He's back in the stripes for Super Street Fighter IV with the orange one as DLC.
 * Terry Fawles in Phoenix Wright Ace Attorney: Trials and Tribulations wears old-fashioned stripes, complete with ball and chain. However, all the other prisoners (such as Maggey Byrde, who spent nearly a month in solitary due to a rigged trial) seem to retain their civilian clothing, which makes one really wonder about poor Terry...
 * The "heroes" in both Manhunt games, coming from death row in the first and an asylum in the second.
 * Jack's standard outfit in Mass Effect 2 is an orange prison jumpsuit (you did just break her out of prison after all), with the top half draped off to show off her chest tattoos.
 * The prison in The Suffering has a very 1920s-30s feel to it (including guards with Tommy guns), but the prisoners all wear modern orange jumpsuits.
 * In the intro of Jak II Renegade Jak wears a dark green jumpsuit before being rescued by Daxter. The front of it says CRIMI⅃AИ in the in-game writing system (the last three letters mirrored) and on his leg is "CELLB".
 * In Batman: Arkham Asylum, the Blackgate Penitentiary inmates either wear dirty white pants with no shirt, or (if they're the psychotic High Security Inmates) orange scrubs with restraints, chains, and headgear that prevents them from biting.
 * In Portal, Chell is wearing an outfit very reminiscent of prison garb, which makes sense because she is imprisoned in a "research facility" as a human lab rat. In the sequel, she is wearing largely the same jumpsuit, undone to the waist to reveal a white undershirt.
 * In Ghost Trick, Detective Jowd and the other inmates of the special prison wear the traditional striped uniforms.

Web Comics

 * The KAMics: When Gertrude and Brunhilda are captured by King Jason, they're put in blue striped, midriff-bearing outfits with pillbox hats.
 * Last Res0rt Shows the prisoners being brought in and performing on the first episode in bright orange jumpsuits. The volunteers are also wearing these outfits during the first episode -- but since Xanatos is the only volunteer NOT to become an executioner, he ends up tossed in with the prisoners as well, and keeps his outfit.
 * In Everyday Heroes,  and her cellmates wore the all-orange baggy shirt and trousers, as did   and his henchmen.
 * In The Lydian Option prisoners all wear magnetic arm cuffs to enable easy restraint.

Western Animation

 * Kim Possible's bad guys all end up with orange jumpsuits.
 * The Simpsons: Sideshow Bob, for some reason, wore his prisoner orange jumpsuit under his regular clothes when he had gone straight and moved to Italy.
 * The striped prison outfit and the jumpsuit prison outfit both appear in Danny Phantom. Wulf wears the jumpsuit type.
 * Batman the Brave And The Bold
 * The defeated is placed in prison stripes, cap and all. No shoes, though.
 * Various villains who have just escaped from prison, or are in the process of escaping from prison, appear to be wearing prison stripes over their costumes. Or at least are allowed to keep their distinctive headgear.
 * And in the Music Meister episode all the Arkham inmates are shown to wear either prison stripes or straitjackets--bar Clock King, seen working out in a wifebeater and a doorag, for some reason.
 * The stripes and the orange jumpsuits turn up on The Powerpuff Girls.
 * Escaped Luthor on Justice League Unlimited wears the Orange Prison Fatigues.
 * Cosmo and Wanda in The Fairly Odd Parents: "School's Out" end up in the black and white stripes when Jorgen puts them in jail.
 * Jimmy Two-Shoes uses the traditional black and white stripes.
 * The criminals in Belle Reve prison on Young Justice all wear the orange jumpsuits.
 * Prince John, Sir Hiss, and the Sheriff of Nottingham at the end of Robin Hood.
 * In the dog pound scene in Lady and the Tramp, the shadows of the cages the dogs are kept in resemble prison stripes when reflected onto the dogs' fur.

Anime & Manga

 * Played with in Code Geass, where (some) prisoners are restrained in the same way as mental patients. C.C. wears prison garb, a sort of odd, undone straitjacket, as her default outfit in season 1. Apparently, these are only given to women, since later on  wears the same type as C.C. while all the male prisoners wear more traditional straitjackets.

Films -- Animation

 * One of the weasels from Who Framed Roger Rabbit? has a half-done straitjacket on, in lieu of the zoot suits worn by the other weasels.

Films -- Live-Action

 * Terminator 2: Judgement Day has Sarah Connor in the scrubs, including the accoutrements that could be used as weapons, though she found a way anyway.
 * Dead Again has people in scrubs, straitjackets or both on top of normal clothing or pajamas.

Live-Action TV

 * Quantum Leap has people in scrubs on top of normal clothing or pajamas.

Pro Wrestling

 * TNA wrestler Abyss wrestles in the white scrubs from the mental hospital he was placed in (which have his last name, "Park", stenciled on the back, for some reason) after he was freed from James Mitchell.
 * Mike Shaw wore pajamas from a mental institution when he was competing as "Norman the Lunatic" in the N.W.A..

Video Games

 * Psychonauts uses both the "straitjacket" and "rags" versions of the "mental institution" type: Fred wears a straitjacket, and Gloria has a tattered dress.
 * Both of these are actually costume options for the mentally unbalanced Psymon Stark in SSX 3; One of his alternate shirts is a straitjacket, and one of his alternate bottoms is a pair of orange prison scrubs called "Standard Issue." Note that Psymon has had his trouble with the law before, as well.
 * In Batman: Arkham Asylum, a few of the villains (Zsasz, Ivy, and Croc) are wearing asylum-issued orange clothing, though they take steps to emulate their usual getups. Croc and Zsasz go shirtless, whilst Ivy goes around without pants. There's also hordes of "Arkham Lunatics" who are released midway through the game, who wear white scrubs and are covered in restraints.
 * In Dead Space 2, protagonist Isaac Clarke wakes up in a straitjacket. It's pretty inconvenient, seeing how there's a Zombie Apocalypse going on and he can't fight back.
 * In Dead Space 2, protagonist Isaac Clarke wakes up in a straitjacket. It's pretty inconvenient, seeing how there's a Zombie Apocalypse going on and he can't fight back.

Web Original

 * In Kate Modern, the inmates of St. Grinstead Psychiatric Research Institution wear plain grey pajamas. Straitjackets are reserved for especially dangerous patients, such as the infamous Patient #12.

Western Animation

 * Batman the Animated Series has the villains in their normal costumes with straitjackets on top in some episodes, or in scrubs in others.
 * The Joker wore an oversized straitjacket in his early appearances on The Batman, later donning the traditional purple suit.
 * Sometimes the women wore short dresses (like in the lobotomized Ivy in the Justice Lord's Universe in Justice League Unlimited, and BTAS' tie-in comics.
 * The Twisted Whiskers Show has Dine & Dash, two thieving cats who have the "mask" design to their fur, and the black and white jailbird stripes as a pattern in their fur.