History OohMeAccentsSlipping / LiveActionTV

* ''TimeTrax'': This was known to happen in a show set mostly in the US (although at least one episode was set in London), filmed in Australia. (And yes, they had one or two episodes set in Australia.)

North Sea."

* ''Series/{{Angel}}'' and ''Series/BuffyTheVampireSlayer'': Both shows have Angel affect a somewhat inconsistent Irish accent during flashbacks. Notably, in a later episode in which he [[LaserGuidedAmnesia loses the memories]] of everything since before he was vamped, the writers had him speaking in American dialect (and being confused by it himself), because his Irish accent had an American accent.

* ''Series/BandOfBrothers'': As many of the actors were British, there was a chance for accents to slip. In episode 3, "Carentan", one can hear Rick Warden's (who plays Harry Welsh) natural English accent slip through quite noticeably on several occasions.

* ''Series/BuffyTheVampireSlayer'': Then there is Spike. James Masters does a passable British accent most of the time, but as his presence increases, there are more than a few slips (too round r's, most noticably, or the use of inherently British words such as 'bollocks' a little too much like how an American would say them.) However, during season 4, twice, he has to fake a Southern accent ("I am a friend of Xander's") and the results are (perhaps intentionally) hilarious.

* ''Series/BurnNotice'': Gives us Fiona Glenanne, the former Irish terrorist who can't hold an Irish accent to save her life. Gabrielle Anwar is otherwise fantastic, so after the pilot, they gave her an American accent along with the explanation "I can't very well be talking like a freakin' leprechaun now, can I?" Ahh, ''much'' better.

* ''CharliesAngels'': In one episode, the girls are tasked with protecting a collection of priceless jade. Cheryl Ladd's character gets to pose as the jade's aristocratic Swedish owner, complete with a hilariously terrible accent that has to be heard to be believed. ("Ah love-ah mah yade-ah.")

* StephenColbert: He deliberately changed his accent when quite young, and ''never'' slips back into his original Southern accent - except [[http://www.colbertnation.com/the-colbert-report-videos/167610/may-08-2008/garrett-reisman once]] (fandom consensus was that this was adorable).

* ''Series/{{CSI}}'': One episode has Roger Daltrey playing a long-missing mob boss who's come back to kill his old crew. For most of his appearance, he affects a pretty convincing American accent... but then the character has a heart attack, and after that, he's pretty much speaking in his native accent.

* ''{{Deadwood}}'': Al Swearengen's accent waxes and wanes like the moon. Unlike the real historical figure, Ian [=McShane=] plays him as an immigrant and even mentions Manchester (nearby to [=McShane's=] native Lancashire) within the dialogue. This would explain slippage.

* ''Series/{{Degrassi}}'': Marco's parents, who had quite possibly the most stereotypical Italian accents ever. It slipped in the episode where [[ComingOutStory Marco came out to his father]] and his father talked with a regular Canadian/English voice. Surprisingly, this actually ''worked'' and made the scene a lot better.

* ''Series/DoctorWho'': Had Peri Brown, who was supposed to be from Pasadena, California. However, her actress, Nicola Bryant, a native Briton, apparently couldn't pin down a California accent if she tried and instead took Brits on a linguistic tour of the United States with each episode.

* ''TheDresdenFiles'': Paul Blackthorne frequently slips into an English accent in this TV series, especially during the voiceovers.

* ''Series/{{Firefly}}'': Every so often, Jewel Staite (a Canadian from Vancouver) would let a Canadian "ou" (i.e. aboat) slip into her Wild Western accent. NathanFillion (also Canadian, from Edmonton) also did this, probably most notable in the beginning of ''Film/{{Serenity}}'' where Mal is in the cockpit with Wash. Of course, all the characters on the show come from various planets where many dialects of English and other languages have evolved over centuries.

* ''{{Frasier}}'': One episode required Daphne to fake an American accent, complicated by the fact that the only word she could say in said accent was, "Sure!". This is especially notable considering that Daphne's own English accent is faked by actress Jane Leeves.

* Comedy duo French and Saunders have a running gag where whenever they do a parody of a movie/tv show, they'll lose their accent at some point in the parody (if they bothered with one in the first place). The other one will then say "You're not going to bother with the accent, then?" which prompts the other one to try and get back into the accent by saying "how are you" in a ridiculous way that sounds more like "haaay err yew".
** Their catch-phrase "how are you?" in these situations is done in a Northern Irish accent. Entertainingly lampshaded in their ''{{Star Wars}}'' parody where Saunders played Liam Neeson's character. Since Neeson is Northern Irish, for once the accent was right.

* ''Series/{{Heroes}}'': In the first few episodes of season one, Mohinder has an Indian accent which has been replaced by something resembling a British one. Neither of those are the actor's real accent, which is American. Amusingly, Sendhil Ramamurthy had a guest appearance on ''{{Psych}}'' where, instead of doing the full Mohinder, he tried to go with an accent about halfway between Mohinder's British one and his own natural "California Valley Dude" accent. Instead it just seems to slip between one and the other throughout the episode from scene to scene.

* ''Series/{{House}}'': Stars English actor [[http://youtube.com/watch?v=M5BA9rrrcrs Hugh Laurie]] as the [[FakeAmerican American]] title character [[DrJerk Dr. Gregory House]]. His American is so good (if a little creepy) that when his [[http://youtube.com/watch?v=qC52lMMQYa0 audition tape]] was viewed, executive producer Bryan Singer, unfamiliar with Laurie's nationality or previous work, singled him out as an example of a "real American actor." Laurie has gone on record that after a long shoot his accent drifts towards something more "French sounding." (Note that he tries to keep his American voice all day long even when he flubs a take).

* ''Series/JonathanCreek'': Stuart Milligan, playing American stage magician Adam Klaus, had an accent that notably veered into English on certain long vowels.

* ''LazyTown'': Both Magnus Scheving (who plays Sportacus) and Stefan Steffenson (who plays Robbie) sometimes slip into their native Icelandic accents.

* ''Series/{{Leverage}}'': Dear Gina Bellman, we'll argue about whether or not you're an excellent actress or a poor one. In some way, your power is in that argument. But, the accent, oh, the accent. Whenever you take on a non-Brit accent, it weaves like a drunk.

* ''Series/{{Lost}}'': There are numerous American movie or television shows in which a character has tried and failed to do an Australian accent, often to the point where she doesn't even realise it is meant to be Australian until someone else points it out. Notable for its bad Australian accents is this show, with over five different accents being called "Australian". Only Victoria native Emilie de Ravin does a genuine Aussie accent (and even then, some viewers complained about how "[[RealityIsUnrealistic fake]]" her accent sounded).

* ''TheMentalist'': Australian Simon Baker generally maintains a decent American accent in this show, making it all the more jarring when his "Stay tuned for our next episode" voiceover sounds like "Stay tyuned fer ow' next episode."

* ''Series/{{Merlin}}'': Once in a while on Series 5, Alexander Vlahos's Welsh accent makes a brief appearance.

* ''Series/MontyPythonsFlyingCircus'': In one episode, Eric Idle plays a U.S. movie producer ("Scott Of The Antarctic") with a truly painful-to-listen-to FakeAmerican accent.

* ''MurphyBrown'': Corky Sherwood would slip into a southern drawl whenever she became extremely angry.

* ''Franchise/PowerRangers'': More or less every character after the tenth season ''[[Series/PowerRangersWildForce Wild Force]]''; though the characters were always American, usually Californian, the actors were predominantly from New Zealand and Australia, and the accents were invariably transient. Until Haim Saban bought back the franchise, the last season in which the Ranger actors were primarily from North American was ''Series/PowerRangersSPD'', though Monica May (Z) was the only American; the other actors were Canadian.
** Averted in ''Series/PowerRangersMysticForce'' with Xander, who was from Australia, allowing his actor, Richard Brancatisano, to use his native accent.

* ''{{Psych}}'' has an in InUniverse example--a fortune teller speaks with an eastern European accent until things get really serious, and then it totally disappears.

* ''Series/RedDwarf'': Robert Llewellyn's accent as Kryten (which was meant to be Canadian, but really ''really'' isn't) changes to Llewellyn's own Northampton accent in one brief scene in the episode "Polymorph" ("It's here..." -- "Where?" -- "Somewhere...").

* ''Series/{{Revolution}}'': Creator/DavidLyons, in trying to be FakeAmerican, suffers from this from time to time.

* Portia de Rossi: Her accent isn't too bad but there are times when her accent slips up.

* ''TheSecretCircle'': Phoebe Tonkin (an Australian actress) is playing Faye (a girl living in Washington). In the pilot, at least, it is painfully obvious that she is Australian. She seems to be getting better as the series progresses, though.

* ''Series/StarTrekTheNextGeneration'': At the start, Deanna Troi spoke with a pronounced Eastern European accent that softened over time to an mid-Atlantic accent somewhat closer to her natural English accent. Her mother, Lwaxana Troi, has no such accent. After Marina Sirtis called the producers on this, they decided she must have been using her father's accent. Then, in a later episode, an illusion of her father shows up sounding nothing like her either.

* ''Series/StarTrekTheOriginalSeries'': In the episode "The Doomsday Machine", James Doohan (Scotty) noticeably lapses into his native Canadian accent at one point.

* ''TheSuiteLifeOnDeck'': An episode where the group goes to the author of SherlockHolmes' [[JustForPun home]], the original draft of the first Holmes story, which is on loan from the Queen's library, is stolen. Cody then tries to figure out who the thief is, and succeeds, as a supposed British detective stole the book, which Cody figured out because his accent slipped, saying 'fries' instead of the more British 'chips', revealing that he is Belgian.

* ''Series/TrueBlood'': Stephen Moyer occasionally slips into his native British accent in a painfully obvious way.

* ''WhoseLineIsItAnyway'': In one episode, they play "the German edition of ''WhoWantsToBeAMillionaire''", [[http://au.youtube.com/watch?v=7OBNUNZsb9Y=related and Greg comments, "und if my accent slips to another country, you may call me on zat."]]

* ''TheWire'': Actor Dominic West (born in Yorkshire, England) played a Baltimore detective in the HBO series. He is supposed to have a stylized Baltimore accent, but he lapses into his British accent in the second-last episode of the first season during a conversation with a [[http://youtube.com/watch?v=xg_3ZSeHL4g district attorney]]. Stranger still, at one point during the show's second season, his character (Jimmy [=McNulty=]) attempts to speak like a British man to impress his fellow detectives, but ends up speaking in a highly exaggerated tone that is nothing like his original accent. Near the end of episode 3.4, as well, West blatantly slips when asking "You ever been down the ocean?"

* ''XenaWarriorPrincess'': LucyLawless (another Kiwi) suffered serious vowel slippage in what was, presumably, supposed to be a FakeAmerican; in all fairness to Lawless, though, that was hardly the greatest of the series' anachronisms.

* ''Series/{{The X-Files}}'': Canon has it that Mulder was born in Massachusetts, but David Duchovny plays him without any real accent. Which made it even more amusing to have heard Agent Mulder once lapse into Duchovny's own New Yorkese when he was angrily calling someone "stoopid".

* ''Series/{{Alias}}'': In a particularly bizarre example, in one episode, Sydney and Vaughn are portraying a French couple with requisite over-the-top faux accents--which is odd when one realizes that Michael Vartan is French-born. However, in the same scene, Vaughan speaks to their mark in perfect French, no trace of the false accent.

* ''Series/BurnNotice'': The hero's ex-girlfriend Fiona is supposed to be Irish. After making the audience suffer through Gabrielle Anwar's ''extremely'' poor job at faking an Irish accent in the pilot episode, the creative staff decided to face up to the reality that she simply couldn't pull it off. Voila, episode 2 of the show has Fiona announcing that since she was living in America, she was going to work on 'faking' an American accent, and the horrible faux-Irish speech went over the side.

* ''Series/{{Chuck}}'': Yvonne Strahovski uses her natural Australian accent when impersonating a scientist in one brief scene. She also spoke Polish (which is her actual first language) for a single line in an earlier episode. She's said the American accent gives her the most trouble on the word "girlfriend," but she slips very rarely.

* ''Series/DoctorWho'': In the episode "Tooth and Claw", the Tenth Doctor affects a Scottish accent in order to blend in as a native of the Scottish highlands. Later in the episode, he forgets to continue using the accent and is caught by Queen Victoria. Notable for the fact that DavidTennant, the actor playing the Doctor in the episode, is in fact Scottish, and normally affects an Estuary English accent when playing the role.

* ''Series/GameOfThrones'': Most American actors do an excellent job of mimicking British-sounding accents, but sometimes an American twang can slip through, especially when they are angry. Peter Dinklage tends to get the most criticism in this regard.

* ''TheNanny'': In one episode, Fran Drescher's character loses her trademark nasal voice after eating a lot of wasabi. Though the effect is only temporary, it allows the audience to hear her real voice.
** It's not quite her real voice- Fran Drescher literally has to talk a lot slower to sound less Fran-ish.

* ''WhiteCollar'': Diana (Marsha Thomason) goes undercover as a journalist's personal assistant and puts on her natural British accent to play up her qualifications, as the journalist studied in England and would be more likely to hire someone from there.

* ''Series/ThirtyRock'': Phoebe's British accent. Her actress, Emily Mortimer, actually is British, making her a Brit-playing-an-American-playing-a-Brit.

* ''{{Friends}}'': One episode had Ross inexplicably starting to teach a new class in a horrible British accent. His attempts to "gradually phase it out" as he "adapted" to America made it even worse.

* OrphanBlack: When the clones (who include an American, two Canadians, a punky English immigrant to Canada, a German and a Ukrainian) try to impersonate each other they don't always get it right. In particular, Alison's impersonation of Sarah in the fourth episode. Actually pretty good acting on the part of Tatiana Maslany, who handles all the clone characters.

*** Alexis Denisof apparently also slipped now and then on words like "data".

* ''{{Friends}}'': Happens InUniverse in the episode "The One with Ross's Tan". When Monica and Phoebe's old friend returns from England, she fakes a British accent. At one point, she says "I feel like a perfect arse", pronouncing "arse" like a pirate says "arr".

* ''Series/StarTrekTheNextGeneration'': At the start, Deanna Troi spoke with a pronounced Eastern European accent that softened over time to an approximation of her real, English accent. Her mother, Lwaxana Troi, has no such accent. After Marina Sirtis called the producers on this, they decided she must have been using her father's accent. Then, in a later episode, an illusion of her father shows up sounding nothing like her either.

*** It is, however, completely subverted by John Mahoney, who was also born and lived in England during his childhood. He pulled off a Manchester accent during a "dream sequence" episode once flawlessly.
*** Jane Leeves's weird and allegedly Mancunian accent in ''{{Frasier}}'' was developed by the actress as a generic approximation of a North-Of-England accent - ie, a British accent that would sound more palatable to American ears - despite it not being at all realistic or representative of any one geographical part of England at all.

* ''Series/{{GraceLand}}: Mike is going undercover and tries to incorporate an accent into his persona. Briggs tells him to knock it off since his accent is terrible and it will automatically make their targets suspicious. Unless Mike can do the accent flawlessly, he should just use his normal accent.

* OrphanBlack: When the clones try to impersonate each other they don't always get it right. In particular, Alison's impersonation of Sarah in the fourth episode. Actually pretty good acting on Tatiana Maslany's part.

* ''LegendofWilliamTell'' Beth Allen and Kieran Hutchinson, both New Zealand, do very well generally with occasional slips. Most of the extras slide closer to NotEvenBotheringWithTheAccent.

* ''{{Friends}}'': Happens InUniverse in the episode "The One with Ross's Tan". When Monica and Phoebe's old friend returns from England, she fakes a British accent. At one point, she says "I feel like a perfect arse", pronouncing "arse" like a pirate says "arr".
* ''{{Charmed}}'': It was Julian [=McMahon=]'s first role that required him to use an American accent, and as such his native New South Wales(Australian) accent breaks through a few times in the early Cole episodes. It tends to happen on the last word or two of his lines.
* ''Series/{{Copper}}'': An InUniverse example in one episode: A Confederate spy is masquerading as a government representative from Ottawa, and speaking with a [[CanadianAccents French Canadian accent]], but slips and says "y'all", which exposes him as a being from the South.
* ''Series/{{Revolution}}'': David Lyons, in trying to be FakeAmerican, suffers from this from time to time.
* ''Series/{{Merlin}}'': Once in a while on Series 5, Alexander Vlahos's Welsh accent makes a brief appearance.
** So does Colin Morgan's Irish accent.
* ''CriminalMinds'': Jayne Atkinson was originally born in England but moved to the U.S. (first in the Miami area) when she was nine. Her own accent is thus a hybrid of the English and American accents, but on the show she goes for a more authoritative baritone (to more closely mimic Thomas Gibson's portrayal of [[NamesTheSame Hotch]]), which she doesn't always hold.

* ''Series/{{Rome}}'': Kevin [=McKidd=] kept slipping in and out of his native Scottish accent.
* ''Series/{{Heroes}}'': In the first few episodes of season one, Mohinder has an Indian accent which has been replaced by something resembling a British one. Neither of those are the actor's real accent, which is American. Amusingly, Sendhil Ramamurthy had a guest appearance on ''{{Psych}}'' where, instead of doing the full Mohinder, he tried to go with an accent about halfway between Mohinder's British one and his own natural "California Valley Dude" accent. Instead it just seems to slip between one and the other throughout the episode from scene to scene.
** Whenever Sendhil is using his natural accent, like on ''Psych'', there are people complaining how "his fake American accent" is so unconvincing, and he should stick to "his natural British accent". He's from Texas.
** In fact, Sendhil has admitted to doing an intentional OohMeAccentsSlipping on ''Heroes'' because the producers changed their minds about what accent he should have after they'd already filmed the pilot. (This would certainly explain why HaydenPanettiere speaks with a slight Texan inflection when playing Claire to begin with (she and the Bennets live in Texas) that soon disappears.) So for the first few episodes, he attempted to gradually transition from "Indian" to "British."
** And then there's Robert Knepper, who puts on a truly fascinating trainwreck of an accent which slips around various American and British tones with every other word.
*** According to Knepper in an interview, he admits that the slip-ups are deliberate to make Samuel more "worldly."
*** If you're Danish, his last name is a source of never ending hilarity.
** The actress who plays Matt Parkman's wife[=/=]ex-wife Janice is Australian, and her Australian accent slips through on occasion in her scenes with Matt.
* ''Series/{{Cult}}'': Stars Robert Knepper, and he's doing basically the same accent he used on ''Heroes.''
* ''WhoseLineIsItAnyway'': In one episode, they play "the German edition of ''WhoWantsToBeAMillionaire''", [[http://au.youtube.com/watch?v=7OBNUNZsb9Y=related and Greg comments, "und if my accent slips to another country, you may call me on zat."]]
** This happens quite often any time a player is required to fake an accent. Other players would often take notice and point it out, lightly disrupting the scene. In some cases, a player's accent may shift multiple times in a single game.
** The most memorable example of this was in a game of "Hollywood Director" where the performers were all playing Spanish characters. Ryan forewarned that his Spaniard "had a bit of Italian in him", Kathy's Spanish maiden was more French than anything else, and Wayne's Zorro was a stereotypical Mexican. "Funny how we all come from a different part of Spain!" observed Ryan.
** Ryan had another moment of hilarity regarding his accent while playing a game of Whose Line. Despite playing Louis XVI, Ryan spoke mostly in an Italian accent, which he quickly justified by saying that while they were on vacation in Italy, he picked up the language. Once the game was over, he proved he could have spoken in a French accent if he wanted to, but claimed "it was more fun in Italian."
*** In the same skit Colin {{lampshade|Hanging}}d his slippage beforehand with "I'm so panicky that I'm sure my accent will go all over the place."
** You'd think that with all the times Ryan has been told to do a specific accent but used Italian instead, telling him to do an Italian accent would mean he could finally do it correctly. Wrong. ''Danish.''
** In one skit, Ryan lampshades the cast's track record with accents and declares at the start that he's NotEvenBotheringWithTheAccent. As always, the RuleOfFunny applies.
** It was lampshaded again in a game of Scenes from a Hat: Celebrity Endorsements Doomed to Fail.
--->'''Wayne:''' The ''Whose Line'' guide to accents.
** The original British version occasionally called for fake American accents (Paul Merton in particular just sounding like a Londoner in dire pain) and, at least once, for Ryan and Colin to do "Shakespeare," which was cruel.
*** Also in the British version, Colin did such a spectacularly awful Scottish accent that he wound up [[http://www.youtube.com/watch?v=FPWuGrNRHzQ referencing it in the American version]]. Hilariously, Colin was ''born'' in Scotland and as a boy took pains to hide his accent.
*** For those who don't know why it's "cruel", Ryan is American and Colin is Scottish-Canadian.
* ''CharliesAngels'': In one episode, the girls are tasked with protecting a collection of priceless jade. Cheryl Ladd's character gets to pose as the jade's aristocratic Swedish owner, complete with a hilariously terrible accent that has to be heard to be believed. ("Ah love-ah mah yade-ah.")
** Kate Jackson's [[EverythingSoundsSexierInFrench French accent,]] heard in a few episodes, isn't much better.
** Their accents in general are hard to distinguish from one another as the change in time has made things different and what was a typical Hollywood accent has changed since then, as have the ones they were faking. They are, however, ridiculously overdone.
* ''MurphyBrown'': Corky Sherwood would slip into a southern drawl whenever she became extremely angry.
** Corky (like Faith Ford) is from Louisiana. As a news anchor, she'd have had to learn to drop the accent on-air, so it makes perfect sense for her to revert when stressed.
* ''TheBigBangTheory'': Sheldon Cooper displays an in-universe version; he once briefly reverted back to his natural accent (East Texas) after being locked out of his apartment. He's done it a couple of times since then, usually when he's upset or excited.
* ''{{Frasier}}'': One episode required Daphne to fake an American accent, complicated by the fact that the only word she could say in said accent was, "Sure!". This is especially notable considering that Daphne's own English accent is faked by actress Jane Leeves.
** Her fake Mancunian accent is pretty unconvincing to British viewers. Jane Leeves is British but was born in Essex and raised in Sussex -- nowhere near Manchester.
*** It is, however, completely subverted by John Mahoney, who was also born and lived in England during his childhood. He pulled off a Manchester accent during a "dream sequence" episode once flawlessly.
*** Jane Leeves's weird and allegedly Mancunian accent in ''{{Frasier}}'' was developed by the actress as a generic approximation of a North-Of-England accent - ie, a British accent that would sound more palatable to American ears - despite it not being at all realistic or representative of any one geographical part of England at all.
*** Alternatively, her accent can be thought of as slipping and sliding along the North Cheshire Plain from Runcorn and Ellesmere Port right across to Stockport and back again... only at the Stockport end of the Grand Tour does it even touch on Manchester, and then on a South Manchester accent. Americans would not have liked North Manchester ''at all'', as this touches on broad Lancashire.... tha' knows, sithee, yon Yanks'd've bin reyt up in't urr.
** Kelsey Grammer's own natural accent is the classic loose Florida drawl (he is, after all, a Floridian) than Frasier's clipped upper-class tones.
* ''{{Brookside}}'': There was a actress in this now-defunct Scouse soap opera who was meant to be from a geographically distinct part of Northern Ireland. Part of the joy of listening to the Dublin-born actress (Barbara Dreman) who played Niamh Musgrove was the way, like an [[UsefulNotes/IrishTravellers Irish traveller]] on the road, her accent moved and wavered between the six counties of northern Ireland without once settling on any one, often in the same line of dialogue. (Again, the Jane Leeves thing of mastering a regional accent from your own country which is not your own.)
* StephenColbert deliberately changed his accent when quite young, and ''never'' slips back into his original Southern accent - except [[http://www.colbertnation.com/the-colbert-report-videos/167610/may-08-2008/garrett-reisman once]] (fandom consensus was that this was adorable).
** He does always pronounce "egg" as "ayg."
* ''TimeTrax'': This was known to happen in a show set mostly in the US (although at least one episode was set in London), filmed in Australia. (And yes, they had one or two episodes set in Australia.)

* ''{{Deadwood}}'': Al Swearengen's accent waxes and wanes like the moon. Unlike the real historical figure, Ian [=McShane=] plays him as an immigrant and even mentions Manchester (nearby to [=McShane's=] native Lancashire) within the dialogue. This would explain slippage.
** In contrast, Paula Malcomson who plays Trixie is originally from Northern Ireland but her accent hardly slips at all.
* ''Series/TrueBlood'': Stephen Moyer occasionally slips into his native British accent in a painfully obvious way.
** The same for many of the actors on the show, as most of them are not native to the American South.
** Though one actress manages to slip into two different Southern accents and random points.
** The show also has in InUniverse example with Russell Edgington, who loses his heavy Southern Accent in favor of a German sounding one when he gets angry. [[JustifiedTrope Justified]] since while he is [[Really700YearsOld older]] than both Germany and the New World he has been a Southerner for a relatively short time, and was a Nazi before that.
* ''Series/DoctorWho'': Had Peri Brown, who was supposed to be from Pasadena, California. However, her actress, Nicola Bryant, a native Briton, apparently couldn't pin down a California accent if she tried and instead took Brits on a linguistic tour of the United States with each episode.
** And, it didn't help authenticity that she was told not to use American terms like "truck" or "elevator" in favor of British ones like "lorry" and "lift" because the BBC thought [[ViewersAreMorons it'd confuse the audience]]. Just as the aforementioned "Mancunian" Jane Leeves used Americanisms like "trunk" and "elevator" and "sidewalk" right from Day One, despite her character being from Manchester England and therefore being more likely to say "boot" and "lift" and "pavement".
** Captain Jack Harkness's "American" accent, widely lauded by the British as dead-on, is a particularly egregious example to actual American ears. This despite his excellent acting otherwise, and decades of experience with the accent. As with Peri Brown, the writers make things worse by continually giving him stereotypically British turns of phrase.
*** Somewhat averted by the fact that Captain Jack is from the far future and never specifically claims to be American. Also somewhat averted because Jack spent more than a century living in Britain near Cardiff.
** DavidTennant, although rarely, does slip into his Scottish accent a few times, mostly on the word "creature"
*** The writers intentionally had some fun with this for the episode "Smith and Jones". The syllable "-oon" is particularly hard for him to say without sounding Scottish, so they gave him the line "Judoon platoon upon the moon".
*** During "The Impossible Planet," when they walk through the corridors and he says the line about how the base was built. It's almost entirely Scottish.
*** If you listen closely to the Doctor and Wilf saying goodbye in "Journey's End", half of what David says is noticeably Scottish. Particularly the lines "They've all got someone else" and "You can never tell her"
*** "Tooth and Claw" had a kind of in-universe example, since they were in Scotland and Ten was faking a Scottish accent (a little broader than Tennant's native one). When the MonsterOfTheWeek shows up and he drops back into the Doctor accent, the Queen calls him on it.
*** His accent drops noticeably towards the end of "Time Crash," such as on the word 'trainers'. This actually works very well, as it crosses strongly into meta.
*** He has noticable problems with the word "ood".
** Paul [=McGann=]'s Eighth Doctor has a subtle case of this. His accent travels a sort of spectrum between [[BritishAccents Received Pronounciation and Scouse]]. Sometimes it's more of one, sometimes it's more of the other. And sometimes it's something in the middle which is sexier than either extreme. It's mostly more on the posh side, but note how he pronounces, "I don't believe in ghosts" -- his accent veers off OopNorth.
*** To be fair this is pretty much Paul's standard "acting" accent - he rarely uses his natural, noticeably Scouse voice in his roles, including his extensive voiceover/narration work.
*** He acknowledges it in the commentary; apparently he was too tired to stick to his "acting" accent.
** River Song may be an almost extreme case. Her first few lines are in some strange very light semi-African accent, then never again.
* ''TheDresdenFiles'': Paul Blackthorne frequently slips into an English accent in this TV series, especially during the voiceovers.
** In an amusing InvertedTrope, Terrence Mann's fake British accent slips occasionally into his native southeast US one. It's most noticeable when he pronounces names like "Lafayette."
* ''TheSarahConnorChronicles'': Normally Lena Heady's American accent is flawless, but in exactly one spot - it's very hard to catch - her accent slips at the end of a sentence, during one of Sarah's end of the episode monologues. (This troper can't remember which episode, though - she'll have to rewatch to find it.)
* ''Series/{{Leverage}}'': Dear Gina Bellman, we'll argue about whether or not you're an excellent actress or a poor one. In some way, your power is in that argument. But, the accent, oh, the accent. Whenever you take on a non-Brit accent, it weaves like a drunk.
** Which might be part of the point, if you really think about it. Most of her marks are American businessmen. In one episode ("The Rashomon Job,") she mentions that to Americans, all accents sound the same (during the various flashbacks, the members of her team portray her accent as Cockney, Scottish, and pure indecipherable gibberish.) It might be possible that Sophie isn't trying to sound authentic in her cons, but is trying to sound the way her target expects her to sound.
* ''HancocksHalfHour'': Parodied in the episode where Hancock's character is a ham actor on a radio soap whose "rustic" accent keeps mutating from Welsh to Cornish to Robert Newton.
* ''ShortlandStreet'': At one point had an American neurosurgeon and one character's British paramour, both of whose actors started slipping into New Zealand accents after about a week.
* ''Series/BattlestarGalacticaReimagined'':
** In the episode "The Son Also Rises", [[spoiler:Baltar]]'s defense lawyer, played by London-born Irish/German actor Mark Sheppard, fades between the character's vaguely American accent and a vaguely British/Irish accent.
** During the same trial, English actor JamieBamber, who plays Lee "Apollo" Adama with a pseudo-American accent, slips up and says, "Chamallar extract," adding in an "r" sound after "Chamalla," which is a British-ism.
*** And while Bamber did an admirable job on the whole in the series, his accent in the mini-series does slip on occasion, though this is partly forgivable since the series isn't set in the real world at all but in a made-up set of planets, and his accent was faked more for the purpose of matching EdwardJamesOlmos's than in order to sound like an actual American.
*** Perhaps the best example of a slip came in 2008, when the cast appeared on David Letterman's show to do the Top Ten List. Bamber's line consisted of technobabble, which he recited in an American accent in the rapid-fire manner of Adama, before clearly dropping the accent as he suddenly declared "I don't know what the hell I'm talking about". FridgeBrilliance kicks in when you realize that he probably did that ''deliberately'', seeing as how he was breaking character.
*** Bamber has similarly slipped up or struggled to maintain an American accent (despite an overall good job) during some of his appearances on other American TV shows--''Series/ColdCase'' (sure enough, during a "highly emotional scene"), CSIMiami, and 17th Precinct (an unaired pilot). Very tellingly, the latter two came after several years of him using his normal accent while on LawAndOrderUK, so one can assume he was simply out of practice.
** Tahmoh Penikett slips into his own Aboriginal/Inuit accent regularly in the first season and half. In the episode "The Farm" it's especially pronounced for some reason; his "Watchya doin thair Staarbuck" is a particularly good example of a Northern Native cadence.
*** His "normal" accent is more complicated: his father, Tony, moved to Canada from Great Britain in 1957 when Tony was 12, and still noticeably has an English (Sussex) inflection when he speaks, which influenced his son.
** Michael Trucco falls into this a lot; he was born in Canada and moved to the US as a teen. His accent tends to bounce back and forth across the border, especially as he spent more time on the show. He would even pronounce words in different ways within the same episodes.
* ''TheMentalist'': Australian Simon Baker generally maintains a decent American accent in this show, making it all the more jarring when his "Stay tuned for our next episode" voiceover sounds like "Stay tyuned fer ow' next episode."
** While usually Simon Baker has a good American accent he does slip up a lot on words like talk, walk, awkward, awesome and similar ones with the same sound.
*** It also happens when his voice is very low.
** Castmate Owain Yeoman (a Welshman) does a very good American accent, but when he loses it, he loses it big. Not just a word here or there but a full sentence sometimes slips.
* ''Series/BurnNotice'': Gives us Fiona Glenanne, the former Irish terrorist who can't hold an Irish accent to save her life. Gabrielle Anwar is otherwise fantastic, so after the pilot, they gave her an American accent along with the explanation "I can't very well be talking like a freakin' leprechaun now, can I?" Ahh, ''much'' better.
** And Anwar is quite English, so her fake American is even better than that.
* ''Series/{{Degrassi}}'': Marco's parents, who had quite possibly the most stereotypical Italian accents ever. It slipped in the episode where [[ComingOutStory Marco came out to his father]] and his father talked with a regular Canadian/English voice. Surprisingly, this actually ''worked'' and made the scene a lot better.
** Almost everyone on the show inexplicably tries to minimize their Canadian raising, particularly in later seasons.
** Dylan Everett's came through "load" and clear in a few scenes, perhaps to emphasize his character's a CountryMouse from northern Ontario, far from home in {{Toronto}}.
* Comedy duo French and Saunders have a running gag where whenever they do a parody of a movie/tv show, they'll lose their accent at some point in the parody (if they bothered with one in the first place). The other one will then say "You're not going to bother with the accent, then?" which prompts the other one to try and get back into the accent by saying "how are you" in a ridiculous way that sounds more like "haaay err yew".
** Their catch-phrase "how are you?" in these situations is done in a Northern Irish accent. Entertainingly lampshaded in their {{Star Wars}} parody where Saunders played Liam Neeson's character. Since Neeson is Northern Irish, for once the accent was right.
* ''Series/StargateSG1'': Though all of the non-alien main characters are American, two of them are played by Canadian actors: Samantha Carter by AmandaTapping and Daniel Jackson by Michael Shanks. In most cases they manage to avoid saying any Canadianisms, but occasionally they slip. (Most often this is on the word "sorry.") Cameron Mitchell's accent seems to waver, too, although that's unclear whether that was the fault of the actor or because the writers couldn't decide or agree on where exactly the character was supposed to be from. Ben Browder was raised in Tennessee and North Carolina, but they eventually stated that Mitchell was from Kansas.
* ''LazyTown'': Both Magnus Scheving (who plays Sportacus) and Stefan Steffenson (who plays Robbie) sometimes slip into their native Icelandic accents.
** Sometimes? Sportacus doesn't even seem to be ''trying'' to hide his accent, though this is most likely because he hails from "an island in the North Sea."
* ''SpartacusBloodAndSand'': John Hannah mostly manages to keep his [[TheQueensLatin Queen's Latin]] intact (despite the frequent [[ChewingTheScenery scenery chewing]]), but there are a couple of occasions where his native Scottish slips through.
* ''Series/PJKatiesFarm'': The main voice actor, PJ Katie, occasionally had her characters randomly gain or lose accents. This is somewhat understandable considering that she did the voices for every single character and everything was done in a single take.
* ''Horrible Histories'': In this TV adaptation, this often happens on purpose when something unexpected, weird, embarrassing or gruesome happens, such as during the Dick Turpin song, the words "that's lame" are in the actor's normal voice, but the rest of them with an altered voice.
* ''TheTudors'': Jonathan Rhys Meyers does a fairly good British accent through seasons one and two. It began slipping a little more obviously in season three, then in season four it appeared that he'd all but given up. I never knew that Henry VIII was actually Irish.
* ''Series/{{Supernatural}}'': Julian Richings - who was born in England but lives in Canada - plays Death with an English accent. At times you can notice a Canadian accent slip in, especially in the season 6 episode "Appointment in Samarra".
* ''Series/SwitchedAtBirth'': While Daphne's actress is deaf in RealLife it's both sporadic and due to a condition that developed in [[DawsonCasting her early 20s]], so she had to learn the speech impediment that someone who was profoundly deaf since they were a toddler (like her character) would have. Sometimes this "deaf accent" (her term) slips.
* ''Series/JustCause'': Australian actress Lisa Lackey plays Alex [=DeMonaco=], an American from UsefulNotes/LosAngeles, but she occasionally slips into her native Australian accent or various regional U.S. accents (particularly NewYorkCity). This is {{lampshaded}} and {{justified|Trope}} in the pilot when Alex tells Whit she was an army brat and traveled all over growing up, specifically mentioning UsefulNotes/{{Australia}}, New York, and East LA as places she picked up accents from.
* ''{{Dollhouse}}'': There's one episode in which MarkSheppard's accent slips right back to his native British on the line "What happened there, Ballard?".
* Tammin Sursok: Poor girl can't catch a break. Since coming to the United States from Australia, where she had both an acting and a singing career, she has only had roles that require an American accent and in nearly everyone, she slips up at some point. Usually, it's pretty convincing, but she has trouble with a few sounds and you can really tell she isn't actually from the US. It's most noticeable in ''PrettyLittleLiars'' and the final season of ''HannahMontana''.
* ''Deadly Women'': This ID series is produced in Australia and it's painfully obvious when watching the dramatizations of events that occurred in the US. The actors are either terrible at maintaining an American accent or they're not even bothering to try. It tends to get downright Narm-y and NightmareRetardant when what's supposed to be [[DeepSouth trailer park trash]] [[AxCrazy going on a killing spree]] instead sounds like [[Film/MaryPoppins she sould be cleaning chimneys with Dick Van Dyke.]] And the few who ''can'' maintain an American accent have forgotten that Australian and American slang terms--"tart", "telly"--aren't identical.
* ''TwoBrokeGirls'': [[AmericanPie Jennifer Coolidge]] attempts a Polish accent as Sophie. It's pretty easy to notice that she's not Polish.
* ''{{It}}'': TimCurry is usually so flawless at American accents that if you've only seen him in American roles, you might be forgiven for not knowing he's actually British. He still slips up sometimes, though. As Pennywise the Clown in the made-for-TV film adaptation of the book, he seemed to be going for a "Chicago gangster" sort of voice (or at least a parody of what a Chicago gangster is supposed to sound like) with occasional touches of Bert Lahr (the actor who portrayed the Cowardly Lion in ''TheWizardOfOz''. However, at one point his natural accent shows through slightly. (Since Pennywise is, of course, a [[EldritchAbomination vaguely arachnoid, soul-devouring metaphysical freak]] who must necessarily be a master of disguise, [[JustifiedTrope that might or might not have been intentional]].)
* Emma Samms: When she [[TheOtherDarrin took over the role of Fallon Carrington-Colby]], had a fake American accent that barely concealed her natural British one.
* ''TheFeastOfAllSaints'': Happens a fair bit in the Showtime miniseries of Anne Rice's story. To get the effect of French Creole characters living in antebellum Louisiana, the cast speak English peppered with French with French accents. As with anything else, some of the actors are very good and consistent with the accent, but most slip up at least occasionally. And then there are those who [[NotEvenBotheringWithTheAccent don't even bother trying.]]
* Claudia Black: Fortunately, her most [[Series/{{Farscape}} notable]] [[Series/StargateSG1 roles]] allow her to use her natural accent (which is a pleasant sounding but unusual mix of Australian and British that people usually assume is a bad attempt at one of those accents anyway.) In her guest appearances on American TV shows (Hercules, Xena, {{NCIS}}, etc.) she tries to use an American accent which always slips near the end of sentences.
* Angela Cartwright: Despite her moving to the U.S. as a very young child, this British-born actor (MakeRoomForDaddy, LostInSpace) never managed to consistently erase faint traces of British vowel sounds from her dialogue.
* ''Series/{{Oz}}'': There's an InUniverse example in this show. John Basil (Lance Reddick) is undercover, going by the name Desmond Mobay and using a Jamaican accent. None of the drug runners in Oz question the accent, but Augustus Hill catches on when it slips for just a second.

* ''TheBigBangTheory'': John Ross Bowie plays Barry Kripke, a character with [[ElmuhFuddSyndwome rhotacism]], though at times slips into his normal speaking pattern.
* ''Series/{{Hannibal}}'': In one of the trailers for this new NBC series, the English Hugh Dancy, playing American Will Graham, slips noticeably when shouting 'FBI!'; the 'i' sound comes out more like 'oi'. Apart from that, it mostly holds up.
* ''The West Wing'': There is the character of Lord John Marbury, played by Welsh Roger Rees, who speaks with an appallingly bad English upper class accent. This is lampshaded at one point with Leo commenting that he doesn't think the accent is real.

* ''{{Psych}}'' has an in InUniverse example--a fortune teller speaks with an eastern European accent until things get really serious, and then it totally disappears.
** Also on ''Psych,'' Liam James (who plays young Shawn in the flashback scenes) sometimes reverts to Canadian raising ("he passed ''oat''.")
* Just a general notice, that blond Australian actresses (with the exception of Yvonne Strahovski[[note]] What makes Strahovski's ability so impressive is that ''English isn't even her first language.'' She grew up speaking Polish, then learned to speak English perfectly (with an Australian accent), and then learned to speak English with a nearly flawless American accent. In a few episodes of ''Series/{{Chuck}}'', she has also convincingly spoken in a Southern accent and a British accent.[[/note]]) seem to be incapable of accurate American accents. Sarah Wynter is the most egregious offender, followed closely by Poppy Montgomery and then Anna Torv. Portia de Rossi isn't too bad, but she slips up every so often. Strahovski does a perfect accent, but it's obvious by the way her mouth moves when she talks that she is speaking in a different manner than normal.
* Poppy Montgomery: She is guilty in ''Series/WithoutATrace'' and ''Series/{{Unforgettable}}''.
* Portia de Rossi: Her accent isn't too bad but there are times when her accent slips up.
** In ''Series/ArrestedDevelopment'' her accent gets sketchy from time to time, especially when she says, "stupid" or "anything".
** She also occasionally strays into her Australian accent in ''Series/BetterOffTed''.
* ''TheSecretCircle'': Phoebe Tonkin (an Australian actress) is playing Faye (a girl living in Washington). In the pilot, at least, it is painfully obvious that she is Australian. She seems to be getting better as the series progresses, though.
** Nick's Aussie comes out when Charles is drowning him to kill Abaddon.
* ''Series/WonderWoman'': The third season has a leprechaun. The Irish accent is limited to the actor saying "me gold" every couple of minutes. "Never talk about me gold!"
* ''Ned's Declassified'': There was a character named OneBite who had a regular American accent. By the next scene, it literally turned into some random Chinese accent. An egregious one at that.
* ''Series/WithoutATrace'': Anthony [=LaPaglia=] and Poppy Montgomery are guilty. Within the realm of possibility that ''Marianne Jean-Baptiste'' has also.
* ''TheSuiteLifeOnDeck'': An episode where the group goes to the author of SherlockHolmes' [[JustForPun home]], the original draft of the first Holmes story, which is on loan from the Queen's library, is stolen. Cody then tries to figure out who the thief is, and succeeds, as a supposed British detective stole the book, which Cody figured out because his accent slipped, saying 'fries' instead of the more British 'chips', revealing that he is Belgian.
** However, the actually British would know that although they say chips more often than fries, saying fries would be perfectly acceptable, making this clue useless.
** Hilariously he is played by real Brit Charles Shaughnessy

* ''WakingTheDead'': Felicite de Jeu may have done this once. She could have been putting on a more French accent than her real one.
* ''Series/{{Firefly}}'': Every so often, Jewel Staite (a Canadian from Vancouver) would let a Canadian "ou" (i.e. aboat) slip into her Wild Western accent. NathanFillion (also Canadian, from Edmonton) also did this, probably most notable in the beginning of ''Film/{{Serenity}}'' where Mal is in the cockpit with Wash. Of course, all the characters on the show come from various planets where many dialects of English and other languages have evolved over centuries.
** Summer's English accent (and dialect) in "Shindig" is also terribly unconvincing. The fact that Badger falls for it challenges willing suspension of disbelief.
* ''Series/{{Castle}}'':
** Nathan Fillion and Stana Katic both drop a little Canadian raising here and there.
** One episode of has an InUniverse example -- a self-help guru who's a Harvard MBA from California but affects a Laotian accent and pretends to be an immigrant because "people want that Horatio Alger crap". When they start grilling him over a murder, he gets flustered and the accent disappears.
** "Almost Famous" has a male stripper named Hans von Manschaft, who speaks with a German accent which he drops immediately upon learning his rival's been murdered. Castle immediately [[LampshadeHanging hangs that lampshade]].

* ''XenaWarriorPrincess'': LucyLawless (another Kiwi) suffered serious vowel slippage in what was, presumably, supposed to be a FakeAmerican; in all fairness to Lawless, though, that was hardly the greatest of the series' anachronisms.
** Listen to her say "out of the ordinary" Season 1 Episode 22, around minute 18.
* ''Series/{{Torchwood}}'': Watch the outtakes where Jack's in hysterics for one thing or another and he usually just [[http://www.youtube.com/watch?v=eYGUeNUz_5Q&feature=related gives up on holding *any* particular accent altogether.]]

* ''Series/BandOfBrothers'': As many of the actors were British, there was a chance for accents to slip. In episode 3, "Carentan", one can hear Rick Warden's (who plays Harry Welsh) natural English accent slip through quite noticeably on several occasions.
** Damian Lewis can be heard using the British pronunciation of "lieutenant."
* ''Series/{{The X-Files}}'': Canon has it that Mulder was born in Massachusetts, but David Duchovny plays him without any real accent. Which made it even more amusing to have heard Agent Mulder once lapse into Duchovny's own New Yorkese when he was angrily calling someone "stoopid".
** Ditto Gillian Anderson. She was born in the U.S. but lived in England until she was in her early teens, and didn't try to shed the accent until she was out of high school. In the very early episodes she'll slip occasionally. In the 2008 movie it can get quite noticeable in Scully's emotional scenes, as Anderson moved back to England after the show ended in 2002, and had to re-learn her American accent all over again for the film.
** The CSM is a government operative from somewhere in the US. One episode speculated that he was born in Baton Rouge, Louisiana, although this was never confirmed. Diphthongs, though, frequently show up William B. Davis' Canadian background.

* ''{{Eastenders}}'': Featured the character of Vicki Fowler, an English - born teenager who had grown up in the USA and spoke with a FakeAmerican accent that kept slipping. By the end of her run on the show, the accent was dropped entirely and she spoke in the same Cockney dialect as the rest of the cast.
* ''Series/{{Angel}}'' and ''Series/BuffyTheVampireSlayer'': Both shows have Angel affect a somewhat inconsistent Irish accent during flashbacks. Notably, in a later episode in which he [[LaserGuidedAmnesia loses the memories]] of everything since before he was vamped, the writers had him speaking in American dialect (and being confused by it himself), because his Irish accent had an American accent.
** Fred on ''Angel'''s Texas accent also kind of came and went at random. It seemed by season 4 she had given up on it altogether.
*** While impersonating Fred, though, Illyria went ''all out'' with y'alls and aint's. It almost seemed hilariously fake.
*** AmyAcker is actually from Texas herself and said that she was happy about being able to use her native accent on the show.
*** In first season ''Series/{{Angel}}'', Irish actor Glenn Quinn was accused of having a poor Irish accent when playing the character of Doyle. In reality, he was asked to affect an American accent on words the editors thought were difficult to understand when spoken in his natural Irish accent.
** Season Three's "The Prom" has Wesley's usually-excellent accent crack on "Thanks for that" when Giles tells him to ask Cordelia to dance.
*** Alexis Denisof apparently also slipped now and then on words like "data".
** "Teacher's Pet" in season one features a person-sized "she-mantis" played by a South African, but speaking with an American accent. For the most part, her accent is impeccable and it's difficult to say where she gets it wrong, but there's something about her [[IAmVeryBritish r's]]. Also, her vowels.
* ''Series/BuffyTheVampireSlayer'': Then there is Spike. James Masters does a passable British accent most of the time, but as his presence increases, there are more than a few slips (too round r's, most noticably, or the use of inherently British words such as 'bollocks' a little too much like how an American would say them.) However, during season 4, twice, he has to fake a Southern accent ("I am a friend of Xander's") and the results are (perhaps intentionally) hilarious.
** The problem doesn't go away when he plays Capt. John Hart on ''Series/{{Torchwood}}'' with an equally slipping British accent.

* ''Series/{{House}}'': Stars English actor [[http://youtube.com/watch?v=M5BA9rrrcrs Hugh Laurie]] as the [[FakeAmerican American]] title character [[DrJerk Dr. Gregory House]]. His American is so good (if a little creepy) that when his [[http://youtube.com/watch?v=qC52lMMQYa0 audition tape]] was viewed, executive producer Bryan Singer, unfamiliar with Laurie's nationality or previous work, singled him out as an example of a "real American actor." Laurie has gone on record that after a long shoot his accent drifts towards something more "French sounding." (Note that he tries to keep his American voice all day long even when he flubs a take).
** In an interview, he mentioned that words such as "coronary artery" are ''extremely'' difficult for him to pronounce in an American accent. Good job he doesn't have to very... oh, of course.
** Similarly, it seemed rather cruel to name an important character "Amber" when a Brit and a New Jerseyian would pronounce those ''very'' differently.
** Interestingly, in a brief scene in which House impersonates a Brit on the telephone, [[HowsYourBritishAccent Laurie uses not his natural accent]], [[AvertedTrope but the same sort of stereotypical, over-the-top "British" accent that a typical American would put on!]]
* ''Series/HowIMetYourMother'': Lampshaded in one episode, when Barney Stinson's painfully over-the-top video resume features Barney being interviewed by a voiceover of himself with a very bad English accent. Narrator Barney's accent switches to Scottish before the voiceover is abandoned altogether.
* ''Series/{{CSI}}'': One episode has Roger Daltrey playing a long-missing mob boss who's come back to kill his old crew. For most of his appearance, he affects a pretty convincing American accent... but then the character has a heart attack, and after that, he's pretty much speaking in his native accent.
** Louise Lombard's British accent slips out quite frequently as Sofia Curtis. You have to wonder why the producers didn't bother just making her character British.
** There's an episode with a supposed South African whose accent was apparently atrocious all the way through.
* ''Series/JonathanCreek'': Stuart Milligan, playing American stage magician Adam Klaus, had an accent that notably veered into English on certain long vowels.
** Ditto Anthony Head, in the few times he played the same role.
*** It was later revealed that Adam Klaus is a FakeAmerican (he's actually Scottish) so this is excusable.
*** Although Stuart Milligan isn't; he's genuinely Boston-born.

* ''Series/RedDwarf'': Robert Llewellyn's accent as Kryten (which was meant to be Canadian, but really ''really'' isn't) changes to Llewellyn's own Northampton accent in one brief scene in the episode "Polymorph" ("It's here..." -- "Where?" -- "Somewhere...").
** And, after the last of Kryten's ''"...with just two minor flaws(/drawbacks)..."'' gags, Danny John-Jules slips out of the Cat's "soul singer"-esque accent into his normal voice when he shouts, "Okay, forget it!!"

* ''Series/AreYouBeingServed'': Mrs. Slocombe tends to affect an awkward Received Pronunciation accent when talking to customers or otherwise trying to appear sophisticated, but lapses into her (and actress Mollie Sugden's) native Yorkshire accent when angry, embarrassed, drunk, or speaking more casually.

* Poppy Montgomery is guilty in ''Series/WithoutATrace'' and ''Series/{{Unforgettable}}''.
* Portia de Rossi, as mentioned, her accent isn't too bad but there are times when her accent slips up.

* Phoebe Tonkin (an Australian actress) is playing Faye (a girl living in Washington) on ''TheSecretCircle''. In the pilot, at least, it is painfully obvious that she is Australian. She seems to be getting better as the series progresses, though.

* The third season of ''Series/WonderWoman'' has a leprechaun. The Irish accent is limited to the actor saying "me gold" every couple of minutes. "Never talk about me gold!"
* In ''Ned's Declassified'', there was a character named OneBite who had a regular American accent. By the next scene, it literally turned into some random Chinese accent. An egregious one at that.
* In ''Series/WithoutATrace'', Anthony [=LaPaglia=] and Poppy Montgomery (as already noted above) are guilty. Within the realm of possibility that ''Marianne Jean-Baptiste'' has also.
* On ''TheSuiteLifeOnDeck'', an episode where the group goes to the author of SherlockHolmes' [[JustForPun home]], the original draft of the first Holmes story, which is on loan from the Queen's library, is stolen. Cody then tries to figure out who the thief is, and succeeds, as a supposed British detective stole the book, which Cody figured out because his accent slipped, saying 'fries' instead of the more British 'chips', revealing that he is Belgian.

* The character Cliff Clavin from ''Series/{{Cheers}}'' originally had a [[HahvahdYahdInMyCah very broad Boston accent]]; over time, the actor John Ratzenberger let it fade out, reverting to his normal speaking voice. The only remnant is the accent on his catchphrase, "Here's a little known fact..." It's odd, however, that Cliff is the ''only'' member of ''Cheers'' who speaks with any sort of regional accent!
* Early seasons of ''Series/GetSmart'' feature Don Adams' using his signature accent (known as "Glicking") far more than in later seasons. Adams commented once that he learned fairly early how little Glicking he could get away with while still getting the idea across.
* There are numerous American movie or television shows in which a character has tried and failed to do an Australian accent, often to the point where she doesn't even realise it is meant to be Australian until someone else points it out. Notable for its bad Australian accents is the show ''Series/{{Lost}}'', with over five different accents being called "Australian". Only Victoria native Emilie de Ravin does a genuine Aussie accent (and even then, some viewers complained about how "[[RealityIsUnrealistic fake]]" her accent sounded).
** The worst example of a failed Australian accent is Claire's mother, Carole, who is portrayed by a British actress. Especially for Australians, her scenes are very hard to watch

* In one episode of ''Series/MontyPythonsFlyingCircus'', Eric Idle plays a U.S. movie producer ("Scott Of The Antarctic") with a truly painful-to-listen-to FakeAmerican accent.

* Felicite de Jeu in ''WakingTheDead'' may have done this once. She could have been putting on a more French accent than her real one.
* Every so often in ''Series/{{Firefly}}'', Jewel Staite (a Canadian from Vancouver) would let a Canadian "ou" (i.e. aboat) slip into her Wild Western accent. NathanFillion (also Canadian, from Edmonton) also did this, probably most notable in the beginning of ''Film/{{Serenity}}'' where Mal is in the cockpit with Wash. Of course, all the characters on the show come from various planets where many dialects of English and other languages have evolved over centuries.

* On ''Series/{{Castle}}'':

* More or less every character in ''Franchise/PowerRangers'' after the tenth season ''[[Series/PowerRangersWildForce Wild Force]]''; though the characters were always American, usually Californian, the actors were predominantly from New Zealand and Australia, and the accents were invariably transient. Until Haim Saban bought back the franchise, the last season in which the Ranger actors were primarily from North American was ''Series/PowerRangersSPD'', though Monica May (Z) was the only American; the other actors were Canadian.

* LucyLawless (another Kiwi) suffered serious vowel slippage in what was, presumably, supposed to be a FakeAmerican in ''XenaWarriorPrincess''; in all fairness to Lawless, though, that was hardly the greatest of the series' anachronisms.

* Watch the ''Series/{{Torchwood}}'' outtakes where Jack's in hysterics for one thing or another and he usually just [[http://www.youtube.com/watch?v=eYGUeNUz_5Q&feature=related gives up on holding *any* particular accent altogether.]]
* At the start of ''Series/StarTrekTheNextGeneration'', Deanna Troi spoke with a pronounced Eastern European accent that softened over time to an approximation of her real, English accent. Her mother, Lwaxana Troi, has no such accent. After Marina Sirtis called the producers on this, they decided she must have been using her father's accent. Then, in a later episode, an illusion of her father shows up sounding nothing like her either.

* As many of the actors in ''Series/BandOfBrothers'' were British, there was a chance for accents to slip. In episode 3, "Carentan", one can hear Rick Warden's (who plays Harry Welsh) natural English accent slip through quite noticeably on several occasions.

* ''Series/{{The X-Files}}'' canon has it that Mulder was born in Massachusetts, but David Duchovny plays him without any real accent. Which made it even more amusing to have heard Agent Mulder once lapse into Duchovny's own New Yorkese when he was angrily calling someone "stoopid".

* In the ''Series/StarTrekTheOriginalSeries'' episode "The Doomsday Machine", James Doohan (Scotty) noticeably lapses into his native Canadian accent at one point.

* ''{{Eastenders}}'' featured the character of Vicki Fowler, an English - born teenager who had grown up in the USA and spoke with a FakeAmerican accent that kept slipping. By the end of her run on the show, the accent was dropped entirely and she spoke in the same Cockney dialect as the rest of the cast.
* Both ''Series/BuffyTheVampireSlayer'' and ''Series/{{Angel}}'' have Angel affect a somewhat inconsistent Irish accent during flashbacks. Notably, in a later episode in which he [[LaserGuidedAmnesia loses the memories]] of everything since before he was vamped, the writers had him speaking in American dialect (and being confused by it himself), because his Irish accent had an American accent.

* Then there is Spike. James Masters does a passable British accent most of the time, but as his presence increases, there are more than a few slips (too round r's, most noticably, or the use of inherently British words such as 'bollocks' a little too much like how an American would say them.) However, during season 4, twice, he has to fake a Southern accent ("I am a friend of Xander's") and the results are (perhaps intentionally) hilarious.

* Actor Dominic West (born in Yorkshire, England) played a Baltimore detective in the HBO series ''TheWire''. He is supposed to have a stylized Baltimore accent, but he lapses into his British accent in the second-last episode of the first season during a conversation with a [[http://youtube.com/watch?v=xg_3ZSeHL4g district attorney]]. Stranger still, at one point during the show's second season, his character (Jimmy [=McNulty=]) attempts to speak like a British man to impress his fellow detectives, but ends up speaking in a highly exaggerated tone that is nothing like his original accent. Near the end of episode 3.4, as well, West blatantly slips when asking "You ever been down the ocean?"

* ''Series/{{House}}'' stars English actor [[http://youtube.com/watch?v=M5BA9rrrcrs Hugh Laurie]] as the [[FakeAmerican American]] title character [[DrJerk Dr. Gregory House]]. His American is so good (if a little creepy) that when his [[http://youtube.com/watch?v=qC52lMMQYa0 audition tape]] was viewed, executive producer Bryan Singer, unfamiliar with Laurie's nationality or previous work, singled him out as an example of a "real American actor." Laurie has gone on record that after a long shoot his accent drifts towards something more "French sounding." (Note that he tries to keep his American voice all day long even when he flubs a take).

* Lampshaded in an episode of ''Series/HowIMetYourMother'', when Barney Stinson's painfully over-the-top video resume features Barney being interviewed by a voiceover of himself with a very bad English accent. Narrator Barney's accent switches to Scottish before the voiceover is abandoned altogether.
* An episode of ''Series/{{CSI}}'' has Roger Daltrey playing a long-missing mob boss who's come back to kill his old crew. For most of his appearance, he affects a pretty convincing American accent... but then the character has a heart attack, and after that, he's pretty much speaking in his native accent.

* Stuart Milligan, playing American stage magician Adam Klaus in ''Series/JonathanCreek'', had an accent that notably veered into English on certain long vowels.

* In ''{{Wishbone}}'' episodes where the literary figure Wishbone plays is English, Wishbone's voice actor, Larry Brantley, attempts a bad English accent which he tends to keep slipping out of.
* Kevin [=McKidd=] kept slipping in and out of his native Scottish on ''Series/{{Rome}}''.
* In the first few episodes of season one of ''Series/{{Heroes}}'', Mohinder has an Indian accent which has been replaced by something resembling a British one. Neither of those are the actor's real accent, which is American. Amusingly, Sendhil Ramamurthy had a guest appearance on ''{{Psych}}'' where, instead of doing the full Mohinder, he tried to go with an accent about halfway between Mohinder's British one and his own natural "California Valley Dude" accent. Instead it just seems to slip between one and the other throughout the episode from scene to scene.

* ''Series/{{Cult}}'' also stars Robert Knepper, and he's doing basically the same accent he used on ''Heroes.''
* In one ''WhoseLineIsItAnyway'', they play "the German edition of ''WhoWantsToBeAMillionaire''", [[http://au.youtube.com/watch?v=7OBNUNZsb9Y=related and Greg comments, "und if my accent slips to another country, you may call me on zat."]]

* In an episode of ''CharliesAngels'', the girls are tasked with protecting a collection of priceless jade. Cheryl Ladd's character gets to pose as the jade's aristocratic Swedish owner, complete with a hilariously terrible accent that has to be heard to be believed. ("Ah love-ah mah yade-ah.")

* On ''MurphyBrown'', Corky Sherwood would slip into a southern drawl whenever she became extremely angry.

* Sheldon Cooper displays an in-universe version on ''TheBigBangTheory''; he once briefly reverted back to his natural accent (East Texas) after being locked out of his apartment. He's done it a couple of times since then, usually when he's upset or excited.
* An episode of ''{{Frasier}}'' required Daphne to fake an American accent, complicated by the fact that the only word she could say in said accent was, "Sure!". This is especially notable considering that Daphne's own English accent is faked by actress Jane Leeves.

* There was a actress in now-defunct Scouse soap opera ''{{Brookside}}'' who was meant to be from a geographically distinct part of Northern Ireland. Part of the joy of listening to the Dublin-born actress (Barbara Dreman) who played Niamh Musgrove was the way, like an [[UsefulNotes/IrishTravellers Irish traveller]] on the road, her accent moved and wavered between the six counties of northern Ireland without once settling on any one, often in the same line of dialogue. (Again, the Jane Leeves thing of mastering a regional accent from your own country which is not your own.)

* Was known to happen in ''TimeTrax''--set mostly in the US (although at least one episode was set in London), filmed in Australia. (And yes, they had one or two episodes set in Australia.)
* In ''Series/RedDwarf'', Robert Llewellyn's accent as Kryten (which was meant to be Canadian, but really ''really'' isn't) changes to Llewellyn's own Northampton accent in one brief scene in the episode "Polymorph" ("It's here..." -- "Where?" -- "Somewhere...").

* In ''{{Deadwood}}'', Al Swearengen's accent waxes and wanes like the moon. Unlike the real historical figure, Ian [=McShane=] plays him as an immigrant and even mentions Manchester (nearby to [=McShane's=] native Lancashire) within the dialogue. This would explain slippage.

* ''Series/TrueBlood'''s Stephen Moyer occasionally slips into his native British accent in a painfully obvious way.

* ''Series/DoctorWho'' had Peri Brown, who was supposed to be from Pasadena, California. However, her actress, Nicola Bryant, a native Briton, apparently couldn't pin down a California accent if she tried and instead took Brits on a linguistic tour of the United States with each episode.

* Paul Blackthorne frequently slips into an English accent on the ''[[TheDresdenFiles Dresden Files]]'' TV series, especially during the voiceovers.
** In an amusing inversion, Terrence Mann's fake British accent slips occasionally into his native southeast US one. It's most noticeable when he pronounces names like "Lafayette."
* Normally Lena Heady's American accent is flawless, but in exactly one spot in TheSarahConnorChronicles - it's very hard to catch - her accent slips at the end of a sentence, during one of Sarah's end of the episode monologues. (This troper can't remember which episode, though - she'll have to rewatch to find it.)
* ''Series/{{Leverage}}''. Dear Gina Bellman, we'll argue about whether or not you're an excellent actress or a poor one. In some way, your power is in that argument. But, the accent, oh, the accent. Whenever you take on a non-Brit accent, it weaves like a drunk.

* Parodied in the ''HancocksHalfHour'' episode where Hancock's character is a ham actor on a radio soap whose "rustic" accent keeps mutating from Welsh to Cornish to Robert Newton.
* ''ShortlandStreet'' at one point had an American neurosurgeon and one character's British paramour, both of whose actors started slipping into New Zealand accents after about a week.

* Australian Simon Baker generally maintains a decent American accent on ''TheMentalist'', making it all the more jarring when his "Stay tuned for our next episode" voiceover sounds like "Stay tyuned fer ow' next episode."

* ''Series/BurnNotice'' gives us Fiona Glenanne, the former Irish terrorist who can't hold an Irish accent to save her life. Gabrielle Anwar is otherwise fantastic, so after the pilot, they gave her an American accent along with the explanation "I can't very well be talking like a freakin' leprechaun now, can I?" Ahh, ''much'' better.

* Though all of the non-alien main characters in ''Series/StargateSG1'' are American, two of them are played by Canadian actors: Samantha Carter by AmandaTapping and Daniel Jackson by Michael Shanks. In most cases they manage to avoid saying any Canadianisms, but occasionally they slip. (Most often this is on the word "sorry.") Cameron Mitchell's accent seems to waver, too, although that's unclear whether that was the fault of the actor or because the writers couldn't decide or agree on where exactly the character was supposed to be from. Ben Browder was raised in Tennessee and North Carolina, but they eventually stated that Mitchell was from Kansas.
* In ''LazyTown'' both Magnus Scheving (who plays Sportacus) and Stefan Steffenson (who plays Robbie) sometimes slip into their native Icelandic accents.

* In ''SpartacusBloodAndSand'' John Hannah mostly manages to keep his [[TheQueensLatin Queen's Latin]] intact (despite the frequent [[ChewingTheScenery scenery chewing]]), but there are a couple of occasions where his native Scottish slips through.
* On ''Series/PJKatiesFarm'' the main voice actor, PJ Katie, occasionally had her characters randomly gain or lose accents. This is somewhat understandable considering that she did the voices for every single character and everything was done in a single take.
* On the TV adaptation of Horrible Histories, this often happens on purpose when something unexpected, weird, embarrassing or gruesome happens, such as during the Dick Turpin song, the words "that's lame" are in the actor's normal voice, but the rest of them with an altered voice.
* ''TheTudors''. Jonathan Rhys Meyers does a fairly good British accent through seasons one and two. It began slipping a little more obviously in season three, then in season four it appeared that he'd all but given up. I never knew that Henry VIII was actually Irish.
* In ''Series/{{Supernatural}}'', Julian Richings - who was born in England but lives in Canada - plays Death with an English accent. At times you can notice a Canadian accent slip in, especially in the season 6 episode "Appointment in Samarra".
* In ''Series/SwitchedAtBirth'', while Daphne's actress is deaf in RealLife it's both sporadic and due to a condition that developed in [[DawsonCasting her early 20s]], so she had to learn the speech impediment that someone who was profoundly deaf since they were a toddler (like her character) would have. Sometimes this "deaf accent" (her term) slips.

* There's an episode of ''{{Dollhouse}}'' in which MarkSheppard's accent slips right back to his native British on the line "What happened there, Ballard?".
* Poor Tammin Sursok can't catch a break. Since coming to the United States from Australia, where she had both an acting and a singing career, she has only had roles that require an American accent and in nearly everyone, she slips up at some point. Usually, it's pretty convincing, but she has trouble with a few sounds and you can really tell she isn't actually from the US. It's most noticeable in PrettyLittleLiars and the final season of HannahMontana.
* The ID series ''Deadly Women'' is produced in Australia and it's painfully obvious when watching the dramatizations of events that occurred in the US. The actors are either terrible at maintaining an American accent or they're not even bothering to try. It tends to get downright Narm-y and NightmareRetardant when what's supposed to be [[DeepSouth trailer park trash]] [[AxCrazy going on a killing spree]] instead sounds like [[Film/MaryPoppins she sould be cleaning chimneys with Dick Van Dyke.]] And the few who ''can'' maintain an American accent have forgotten that Australian and American slang terms--"tart", "telly"--aren't identical.
* [[AmericanPie Jennifer Coolidge]] attempts a Polish accent as Sophie on ''TwoBrokeGirls''. It's pretty easy to notice that she's not Polish.
* TimCurry is usually so flawless at American accents that if you've only seen him in American roles, you might be forgiven for not knowing he's actually British. He still slips up sometimes, though. As Pennywise the Clown in the made-for-TV film adaptation of ''{{It}}'', he seemed to be going for a "Chicago gangster" sort of voice (or at least a parody of what a Chicago gangster is supposed to sound like) with occasional touches of Bert Lahr (the actor who portrayed the Cowardly Lion in ''TheWizardOfOz''. However, at one point his natural accent shows through slightly. (Since Pennywise is, of course, a [[EldritchAbomination vaguely arachnoid, soul-devouring metaphysical freak]] who must necessarily be a master of disguise, [[JustifiedTrope that might or might not have been intentional]].)
* Emma Samms, when she [[TheOtherDarrin took over the role of Fallon Carrington-Colby]], had a fake American accent that barely concealed her natural British one.
* Happens a fair bit in the Showtime miniseries of Anne Rice's TheFeastOfAllSaints. To get the effect of French Creole characters living in antebellum Louisiana, the cast speak English peppered with French with French accents. As with anything else, some of the actors are very good and consistent with the accent, but most slip up at least occasionally. And then there are those who [[NotEvenBotheringWithTheAccent don't even bother trying.]]
* Fortunately, Claudia Black's most [[Series/{{Farscape}} notable]] [[Series/StargateSG1 roles]] allow her to use her natural accent (which is a pleasant sounding but unusual mix of Australian and British that people usually assume is a bad attempt at one of those accents anyway.) In her guest appearances on American TV shows (Hercules, Xena, {{NCIS}}, etc.) she tries to use an American accent which always slips near the end of sentences.
* Despite her moving to the U.S. as a very young child, British-born Angela Cartwright (MakeRoomForDaddy, LostInSpace) never managed to consistently erase faint traces of British vowel sounds from her dialogue.
* There's an InUniverse example in ''Series/{{Oz}}''. John Basil (Lance Reddick) is undercover, going by the name Desmond Mobay and using a Jamaican accent. None of the drug runners in Oz question the accent, but Augustus Hill catches on when it slips for just a second.
* Happens InUniverse in the ''{{Friends}}'' episode "The One with Ross's Tan". When Monica and Phoebe's old friend returns from England, she fakes a British accent. At one point, she says "I feel like a perfect arse", pronouncing "arse" like a pirate says "arr".
* ''{{Charmed}}'' was Julian [=McMahon=]'s first role that required him to use an American accent, and as such his native New South Wales(Australian) accent breaks through a few times in the early Cole episodes. It tends to happen on the last word or two of his lines.
* An InUniverse example in an episode of ''Series/{{Copper}}'': A Confederate spy is masquerading as a government representative from Ottawa, and speaking with a [[CanadianAccents French Canadian accent]], but slips and says "y'all", which exposes him as a being from the South.

* Once in a while on Series 5 of ''Series/{{Merlin}}'', Alexander Vlahos's Welsh accent makes a brief appearance.

* ''CriminalMinds''' Jayne Atkinson was originally born in England but moved to the U.S. (first in the Miami area) when she was nine. Her own accent is thus a hybrid of the English and American accents, but on the show she goes for a more authoritative baritone (to more closely mimic Thomas Gibson's portrayal of [[NamesTheSame Hotch]]), which she doesn't always hold.
* In ''TheBigBangTheory'' John Ross Bowie plays Barry Kripke, a character with [[ElmuhFuddSyndwome rhotacism]], though at times slips into his normal speaking pattern.
* In one of the trailers for the new NBC series ''Series/{{Hannibal}}'', the English Hugh Dancy, playing American Will Graham, slips noticeably when shouting 'FBI!'; the 'i' sound comes out more like 'oi'. Apart from that, it mostly holds up.
* In ''The West Wing'' there is the character of Lord John Marbury, played by Welsh Roger Rees, who speaks with an appallingly bad English upper class accent. This is lampshaded at one point with Leo commenting that he doesn't think the accent is real.
* Mrs. Slocombe in ''Series/AreYouBeingServed'' tends to affect an awkward Received Pronunciation accent when talking to customers or otherwise trying to appear sophisticated, but lapses into her (and actress Mollie Sugden's) native Yorkshire accent when angry, embarrassed, drunk, or speaking more casually.

* ''TheNanny'': In one episode, Fran Drescher's character loses her trademark nasal voice after eating a lot of wasabi. Though the effect is only temporary, it allows the audience to hear her real voice.
** It's not quite her real voice- Fran Drescher literally has to talk a lot slower to sound less Fran-ish.
* ''Series/SixFeetUnder'': In one episode, Nate has a hallucination that Brenda is speaking undecipherable Australian slang in an Australian accent -- which is actress RachelGriffiths' real accent.
* ''Series/DoctorWho'': In the episode "Tooth and Claw", the Tenth Doctor affects a Scottish accent in order to blend in as a native of the Scottish highlands. Later in the episode, he forgets to continue using the accent and is caught by Queen Victoria. Notable for the fact that DavidTennant, the actor playing the Doctor in the episode, is in fact Scottish, and normally affects an Estuary English accent when playing the role.
** And for the fact that the Scottish accent the Doctor affects isn't Tennant's regular one.
** There was a very specific reason that the producers didn't use Tennant's regular accent, which was that Eccleston had used his regular accent, specifically a north England accent which turned into an in-series joke. ("Lots of planets have a North!!!) The original intent was to use Tennant's normal accent, but the producers wanted to avoid turning ''Doctor Who'' "into a tour of the U.K.".
*** Of course, the Doctor's had a Scottish accent before - 7th Doctor Sylvester [=McCoy=] used his normal speaking voice in the role.
*** The 8th Doctor as played by Paul [=McGann=] speaks in a much more generic English accent than [=McGann=] himself, whose true voice has a distinct Liverpool lilt.
** In "The Faceless Ones", the alien duplicate of Jamie has Frazer Hines' real-life English accent.

* ''Series/GameOfThrones'': Most American actors do an excellent job of mimicking British-sounding accents, but sometimes an American twang can slip through, especially when they are angry. Peter Dinklage tends to get the most criticism in this regard.
** Similarly, Prince Joffrey occasionally slips into an Irish brogue.
* ''Series/LifeOnMars2008'': One episode of the US version sees Irish actor Jason O'Mara (who is playing New York born Sam Tyler) go undercover as an Irishman, allowing O'Mara to use his own accent. Of course, there's the inevitable scene where his "Irish" accent is shown to slip-up and become "American" again.

* ''Series/{{Alias}}'': In a particularly bizarre example, in one episode, Sydney and Vaughn are portraying a French couple with requisite over-the-top faux accents--which is odd when one realizes that Michael Vartan is French-born. However, in the same scene, Vaughan speaks to their mark in perfect French, no trace of the false accent.
** Even more impressively, though, Vartan in those scene when he speaks English with a French accent sounds ''exactly'' like a French person speaking English with an accent would. (Take it from someone with a degree in French and who has a foreign exchange student from France one summer!)
** Jennifer Garner, on the other hand, fakes multiple accents over the course of the show, and does a ''terrible'' job of it. This is forgivable when Sydney isn't trying to pass as a native speaker of the language in question, but when she is, it's flat-out cringeworthy - her Russian and Japanese accents in particular.
* ''Series/{{Chuck}}'': Yvonne Strahovski uses her natural Australian accent when impersonating a scientist in one brief scene. She also spoke Polish (which is her actual first language) for a single line in an earlier episode. She's said the American accent gives her the most trouble on the word "girlfriend," but she slips very rarely.
** Her accent slips noticeably on the word "orange." Unfortunately, her character Sarah Walker works in a frozen yogurt shop called Orange Orange.

* ''Series/TwentyOneJumpStreet'': Has a glorious example: a Polish exchange student speaks with what sounds like a badly done French accent. Since French and Polish accents sound nothing alike, the result is not so much a slipping accent but an accent that is already crumpled around the actress's ankles and forces her to scuffle through her part.

* In an episode of ''TheNanny'', Fran Drescher's character loses her trademark nasal voice after eating a lot of wasabi. Though the effect is only temporary, it allows the audience to hear her real voice.

* Also in an episode of ''Series/SixFeetUnder'', Nate has a hallucination that Brenda is speaking undecipherable Australian slang in an Australian accent -- which is actress RachelGriffiths' real accent.
* In the ''Series/DoctorWho'' episode "Tooth and Claw", the Tenth Doctor affects a Scottish accent in order to blend in as a native of the Scottish highlands. Later in the episode, he forgets to continue using the accent and is caught by Queen Victoria. Notable for the fact that DavidTennant, the actor playing the Doctor in the episode, is in fact Scottish, and normally affects an Estuary English accent when playing the role.

* In ''Series/{{Buffy|TheVampireSlayer}}'' season 4, the English vampire Spike twice tries to fake an American accent. In this case, however, actor JamesMarsters wasn't using his own accent - just doing a good imitation of a poor imitation of one.
* Most American actors in ''Series/GameOfThrones'' do an excellent job of mimicking British-sounding accents, but sometimes an American twang can slip through, especially when they are angry. Peter Dinklage tends to get the most criticism in this regard.

* One episode of the US version of ''Series/{{Life On Mars|2008}}'' sees Irish actor Jason O'Mara (who is playing New York born Sam Tyler) go undercover as an Irishman, allowing O'Mara to use his own accent. Of course, there's the inevitable scene where his "Irish" accent is shown to slip-up and become "American" again.
* On ''Series/BurnNotice'', the hero's ex-girlfriend Fiona is supposed to be Irish. After making the audience suffer through Gabrielle Anwar's ''extremely'' poor job at faking an Irish accent in the pilot episode, the creative staff decided to face up to the reality that she simply couldn't pull it off. Voila, episode 2 of the show has Fiona announcing that since she was living in America, she was going to work on 'faking' an American accent, and the horrible faux-Irish speech went over the side.

* On ''DarkAngel'', Bronx-born Alimi Ballard played his Caribbean immigrant character Herbal Thought with an accent so thick fans complained about not being able to understand his dialogue. For the second season of the series, Herbal began speaking something closer to standard English, claiming that his wife was making him do it so he could get a better job. ''Dark Angel'' was canceled, but Ballard now plays sharp, well-spoken, highly literate FBI agent David Sinclair on ''{{Numb3rs}}''. Apparently the advice of Herbal's wife paid off for him!
* In one episode of ''TheRiches'', Wayne and Dahlia, played by EddieIzzard and Minnie Driver, affect British accents for one part of a scam. Both Izzard and Driver are British, and use fake AmericanAccents (in her case, a rather thick Hillbilly drawl.) Then you remember that they're playing UsefulNotes/IrishTravellers, and you get even more confused.
* In a particularly bizarre example, in one episode of ''Series/{{Alias}}'', Sydney and Vaughn are portraying a French couple with requisite over-the-top faux accents--which is odd when one realizes that Michael Vartan is French-born. However, in the same scene, Vaughan speaks to their mark in perfect French, no trace of the false accent.

* On ''Series/{{Chuck}}'', Yvonne Strahovski uses her natural Australian accent when impersonating a scientist in one brief scene. She also spoke Polish (which is her actual first language) for a single line in an earlier episode. She's said the American accent gives her the most trouble on the word "girlfriend," but she slips very rarely.

* The Polish actors in ''{{Spellbinder}}'' spoke with their original accent, to reinforce the general [[BuffySpeak parallel universe thing]].
* In ''Series/{{Undercovers}}'', nearly every time Samantha Bloom has to go undercover as someone other than an American, especially when she's blatantly turning on the sex appeal, Gugu Mbatha-Raw breaks out her original English accent.
* Alyssa Milano is an interesting case. She was born and raised in Brooklyn, and so had the aforementioned accent, but she worked diligently to get rid of it in order to have a successful theater career. As a result of this, when she landed her big role on ''WhosTheBoss'', she found it somewhat difficult to get the Brooklyn accent back. On the show, it's very inconsistent until they dropped it altogether.
* ''Series/TwentyOneJumpStreet'' has a glorious example: a Polish exchange student speaks with what sounds like a badly done French accent. Since French and Polish accents sound nothing alike, the result is not so much a slipping accent but an accent that is already crumpled around the actress's ankles and forces her to scuffle through her part.

* ''Series/BattlestarGalacticaReimagined'': When Baltar is accused of making up his background of growing up a poor farmboy on what was considered the most rural and backward colony, James Callis switches his cultured English accent for a rougher, more rural one ([[OopNorth Yorkshire]], in fact) in telling his story about leaving home and learning to speak in a more upscale manner.

* ''{{The X-Files}}'': Agent Mulder is from Southern New England -- but sometimes David Duchovny's New York roots show through.
* ''{{Roswell}}'': Emilie de Ravin ends up letting her Australian accent slip through in a couple of places in her first appearance on the show.
* ''{{Friends}}'': One episode had Ross inexplicably starting to teach a new class in a horrible British accent. His attempts to "gradually phase it out" as he "adapted" to America made it even worse.
** Similarly, in the episode "The One with Ross's Tan", Jennifer Coolidge's 'Amanda Bufamontisi" is an American who has lived in England for long enough to convince herself she has an English Accent. It epitomises Bad English Accent humour. So much so that Lisa Kudrow could barely make it through filming without laughing hysterically...to the point that in one take, she started laughing ''before Coolidge even said anything'' because she was thinking about how funny it was going to be.
* ''Series/TrueBlood'': There is one episode where Eric Northman, a Norse vampire (yes, really) played by a Swede with a neutral American accent, pretends to be a human with a Southern accent. The result is horrifyingly hilarious (and very obviously bad on purpose).
* ''LastOfTheSummerWine'': Edie puts on a ridiculous fake posh southern accent out of social-climbing ambitions, which has a tendency to vanish and be replaced by her natural salt of the earth Yorkshire accent at times of stress.

* ''LawAndOrderCriminalIntent'': In the episode "Chinoiserie", Goren and Eames immediately identify a supposed British lord as a fake by his atrocious accent which keeps jumping around the UK. The outraged impostor, an actor unknowingly hired to play the part as part of a con, keeps insisting that it is "a perfectly valid British musical hall accent".

* When Baltar on ''Series/BattlestarGalacticaReimagined'' is accused of making up his background of growing up a poor farmboy on what was considered the most rural and backward colony, James Callis switches his cultured English accent for a rougher, more rural one ([[OopNorth Yorkshire]], in fact) in telling his story about leaving home and learning to speak in a more upscale manner.
* In ''Series/TwentyFour'', everyone associated with Dana Walsh's past has a typical DeepSouth accent, but she usually doesn't. When she's especially rattled, however, her original accent slips out. (Her actress is originally from Oregon.)
* Phoebe's British accent on ''Series/ThirtyRock''. Her actress, Emily Mortimer, actually is British, making her a Brit-playing-an-American-playing-a-Brit.

* On ''Series/{{Bones}}'', intern Arastoo Vaziri's Middle Eastern accent is faked, and slips completely when he gets irritated at Dr. Saroyan. He was faking being "just-off-the-boat" so he fellow lab workers wouldn't make fun of his genuine Muslim religious beliefs.
* Similarly, on ''Series/{{Castle}}'', a money-making guru named Johnny Vong fakes a just-off-the-boat Chinese accent to make his fake RagsToRiches story that much more plausible.
* Agent Mulder of ''{{The X-Files}}'' is from Southern New England -- but sometimes David Duchovny's New York roots show through.
* Emilie de Ravin in ''{{Roswell}}'' ends up letting her Australian accent slip through in a couple of places in her first appearance on the show.
* One ''{{Friends}}'' episode had Ross inexplicably starting to teach a new class in a horrible British accent. His attempts to "gradually phase it out" as he "adapted" to America made it even worse.

* There is an episode of ''Series/TrueBlood'' where Eric Northman, a Norse vampire (yes, really) played by a Swede with a neutral American accent, pretends to be a human with a Southern accent. The result is horrifyingly hilarious (and very obviously bad on purpose).
* Edie of ''LastOfTheSummerWine'' puts on a ridiculous fake posh southern accent out of social-climbing ambitions, which has a tendency to vanish and be replaced by her natural salt of the earth Yorkshire accent at times of stress.
* DavidTennant's use of his own Scottish burr in "Tooth And Claw" has been detailed above, with The Doctor "pretending" to speak with a Scottish Accent; but Rose's attempt also bears mention here:

* In the ''LawAndOrderCriminalIntent'' episode "Chinoiserie", Goren and Eames immediately identify a supposed British lord as a fake by his atrocious accent which keeps jumping around the UK. The outraged impostor, an actor unknowingly hired to play the part as part of a con, keeps insisting that it is "a perfectly valid British musical hall accent".
* On {{Jessie}} the titular character is from Texas but doesn't have an accent except for a few occasions when she slips into one.