[TheZookie007]

Surprised she hasn't been brought up before in this thread:

the Dalby, Australian-born actress and producer Margot Robbie has pretty much cut her teeth playing USAmerican roles, from Harley Quinn in the DCEU, to Jordan Belfort's wife in the "based on a true story" movie The Wolf of Wall Street (2013), to her Academy Award-nominated portrayal of Olympic skater Tonya Harding in the biopic I, Tonya (2017).

Margot's Brooklyn accent in The Wolf of Wall Street was so convincing that people couldn't believe that she's really Australian.

[Hiram]

Melanie Lynskey - The last of Us - New Zealand.

[TheZookie007]

Melanie Lynskey - The last of Us - New Zealand.

Jeez, is there any American actor on that show?!

[Hiram]

Melanie Lynskey - The last of Us - New Zealand.

Jeez, is there any American actor on that show?!

Well there is Pedro...

[TheZookie007]

Melanie Lynskey - The last of Us - New Zealand.

Jeez, is there any American actor on that show?!

Well there is Pedro...

...who, if I'm not mistaken, was born in Chile, and came to the USA at age 8?

The number of excellent actors on that show who also are not American, rivals that of LOST

[TheZookie007]

Cillian Murphy and Florence Pugh, who both star in Oppenheimer, are both Irish and English, respectively.

[MaxBigfoot]

Cillian Murphy is Irish.  I am shocked.  Deeply shocked.   

[Hiram]

Cillian Murphy is Irish.  I am shocked.  Deeply shocked.   

I don't think he looks Irish mind.

[TheZookie007]

Like most actors from the British Isles, his (various) American accents are very good.

[salem]

Daniel Kaluuya (Black Mirror, Kick Ass 2, Get Out) is British (born in London).

Of course since I posted this, Daniel has gone on to great things: the London-born actor of Ugandan descent portrayed W'Kabi in the MCU blockbuster Black Panther (2018), and won his first Academy Award for Best Supporting Actor portraying the USAmerican political activist Fred Hampton in the 2021 biopic Judas and the Black Messiah.

His very particular accent for Queen & Slim was modeled on people from Columbus, Ohio. Here he is on Jimmy Kimmel Live, speaking in his natural accent.

Daniel has also been in Doctor Who, in the feature length episode 'Planet of the Dead' in 2009

[salem]

I thought I had mentioned him before but:

Alan Cumming, who played the title character's husband's Chicago political fixer in CBS's The Good Wife, is Scottish. He's also played characters who were Russian (in the James Bond movie GoldenEye) and German (Nightcrawler in X-Men 2), among others.

Here he is speaking in his natural accent.

Yes, Alan Cummin has also been in Doctor Who, quite recently in fact, in the episode 'The Witchfinders'

[TheZookie007]

I guess Doctor Who is the British equivalent of NBC's Law & Order franchise: any actor who's anyone has been on it at some point in some capacity

[TheZookie007]

I don't think I've ever watched a complete episode of The Walking Dead so this was news to me: Andrew Lincoln, the actor who plays Rick Grimes, and Lennie James, the actor who plays Morgan, are both British.

Here they are on a ComiCon panel, while Lincoln gets ribbed a bit over how he pronounces the name "Carl" on the show.

[TheZookie007]

Yesterday was the first time I've ever watched any episode of Yellowstone so it was only because I went on Wikipedia to do some background on the show that I learned that  Kelly Reilly, the actress who plays Beth Dutton, is British.

Here she is during a press junket for Season 2, with her TV husband Cole Hauser.

[solvegas]

Looking over this thread, I noticed it is mostly contemporary times British actors/actresses but how about one from 84 years ago, Vivien Leigh who played the character Scarlett O'Hara in the classic movie, "Gone with the Wind" (1939)