How's Your British Accent?

"Jaime: What's this? Jonas: Student ID. You're going to college. You're transferring in from England. How's your British accent?"

- Bionic Woman, "The Education of Jaime Sommers"

A former English soap opera actress, now working in Vancouver on an American show, naturally needs to put on an American accent when playing an American character. This she can do, because she's an actress, y'know?

The bonus comes when her character has to go undercover as a Brit, complete with an eerily accurate "fake" English accent...

Happens surprisingly often, with the fake-fake accent sometimes being intentionally poor.

Of course fake-fake accent is common with the Deep-Cover Agent as well.

Film

 * In The Island, Lincoln Six Echo is a clone of a Scottish man named Tom Lincoln. All clones are brought up speaking with an American accent to avoid confusion. So when Lincoln Six Echo first encounters Tom Lincoln, he's surprised by the other's strange accent. Later on, he "fakes" the accent to trick a mercenary hunting him and makes sure to insert "shite" into a sentence. Ewan McGregor, the actor playing the Lincolns, is Scottish.

Live Action TV

 * On True Blood Englishman Stephen Moyer plays American vampire Bill Compton, and famously struggles to mimic a Louisiana Cajun accent. It must have been a relief when a flashback sequence showed Bill in an English punk rock bar, and Moyer got to speak with his natural voice.
 * In the Bionic Woman episode "The Education of Jaime Sommers", American Jaime (played by English actress Michelle Ryan) has to pretend to be English.
 * And pulled it off flawlessly. This despite the fact that Jamie Sommers (the character) was 1) not an actress and 2) not trained in espionage (a la Sydney Bristow in Alias), and therefore shouldn't have had any training in the proper British Accent.
 * In the Doctor Who episode Tooth and Claw, The Doctor - played by David Tennant with an Estuary English accent - "fakes" Tennant's own Scottish accent to fool Queen Victoria.
 * Actually he uses a different accent. Tennant's own accent is from Paisley whereas the one he uses in Tooth and Claw is an Edinburgh brogue. So Tennant, a Scotsman, is faking another Scottish accent in a series where he speaks in an English accent as a character from outer space.
 * In The Wire, Sheffield-born actor Dominic West plays American police detective Jimmy McNulty, who pretends to be a British businessman to go undercover (so to speak) in a brothel. His accent is terrible.
 * In Buffy the Vampire Slayer, Spike - a British vampire played by American actor - adopts (rather unconvincingly) an American accent. (He apparently asked his British co-star, Anthony Stewart Head, how he would fake the accent. He was told to "Go crazy on the R's".)
 * It sounded a bit like he was lapsing into molespeak. "Oi'm just an owld frriend of Xanderrrrrr's . . . Oh, to hell with it, I'm your man."
 * In the House MD episode "The Socratic Method", the British Hugh Laurie's American titular character fakes an English accent to account for the anti-social hour he is calling a doctor to get further medical history for a patient (and there's at least one piece of fan fiction that claims House was faking again to allow for a crossover with a Friends episode in which Laurie briefly appears, with his native accent).
 * As a bonus for longtime fans, he uses the exact accent used for his previous Upperclass Twit roles in Blackadder and Jeeves and Wooster.
 * Though he does leave in one rhortic 'r'.
 * Spoofed on Psych. Shawn tries to convince a hotel clerk that he's with Interpol by affecting a British accent and then pretending that his natural American accent is faked as part of his cover.
 * In early 2007, Emily Mortimer had a recurring role on 30 Rock which she played with her native British accent. However, it was later revealed that her character was actually an American posing as a Brit. (Mortimer only did one line with an American accent and that was for The Reveal.)
 * Irish Fiona from Burn Notice, played by an English actress with a half-attempted American accent, reverts to her natural English accent to play a good-time girl.
 * Also, a variant: Michael, despite having lived in Miami all his life, keeps his actor's rather obvious North Shore accent; in one episode, he has to pretend to be from Boston...and he talks like someone from Miami faking a Boston accent.
 * A hilarious lampshading in the same show: When Fiona's brother thinks Michael is a fellow Irishman, Michael has to go "undercover" as an American arms dealer. The brother is unconvinced Michael can pull it off, calling his American accent "a little dodgy."
 * This get even better because if you listen closely to Michael speaking "undercover" Michael nearly slips into an Irish accent.
 * In an episode of Six Feet Under, Nate Fisher imagines his girlfriend as an Australian. Rachel Griffiths, who played the girlfriend, is actually Australian.
 * Irish actor Jason O'Mara got to use his native accent when an episode of the American adaptation of Life On Mars had his character, American detective Sam Tyler, go undercover as an Irishman. In America!
 * In an episode of Chuck Sarah has to pretend to be an Australian scientist, allowing Yvonne Strahovski to use her normal accent.
 * In one episode of Dollhouse, Sierra gets imprinted with the personality of an Australian fan, allowing Dichen Lachman to use the Australian accent she grew up with.
 * Additionally, in season 2,
 * In one episode of Alias, the internationally ambiguous Julian Sark pretends to be American. Julian Sark is Russian-born but educated in Britain and spends a lot of time in Ireland. As a result, his character has an Irish-influenced British accent despite being neither Irish nor British. He's played by the American actor David Anders and the American accent the character faked was the actor's native accent.
 * Chuck on Gossip Girl is played by English Ed Westwick. Chuck is obsessed with Blair, who brings back a guy from her summer vacation in Europe who turns out to be a fake-American, his true nationality being British (though the actor is American). So Chuck, being Chuck, fakes an English accent to pull a Bed Trick on Blair... and we have an English actor playing an American character who fakes an English accent as done rather poorly by an American actor.
 * For Yu-Gi-Oh!: The Abridged Series, British creator LittleKuriboh uses a convincingly fake British accent for Bakura.
 * Vicki Fowler arrives in Eastenders with an American twang, having been brought up in Florida by her British mother. The accent wasn't very convincing and after a few months the actress reverted to her native London speech pattern. This was handwaved as a deliberate effort by Vicki to fit in.
 * A few episodes of Nip Tuck feature a British actor playing an American pretending to be British because he thought American women found it sexy. His "fake" British accent is, of course, flawless, but his American accent? Not so much.
 * One of the recurring characters on later seasons of Cheers was French Jerk Henri, who was always trying to steal Kelly away from Woody. Henri was played by American actor Anthony Cistaro. In one episode, Henri hits on a girl, who tells him she doesn't like French guys. Cue Henri, in an American accent, telling the girl that he's really from Portland.