Some of the actors on the Walking Dead are British also.

British and Australian actors are all over the place. They do a great job with the various American accents.

I didn't realize that the guy that plays Steve McGarrett on Hawaii Five-O, Alex O'Laughlin is Australian and of course Simon Baker from The Mentalist. There was someone else that I recently find out was Australian but I don't remember who it was now.

BLF, do you remember Sue Thomas, FBEye? There was a hunk on the show with an Australian accent. He's actually American. He was terrific playing an Aussie.

And here I was so sure both Gunner and Scarlett were Australian (nope)? Actors/actresses who are often heard with accents other than their native tongue:

Hugh Jackman

Nicole Kidman and Keith Urban

Rebel Wilson

Chris Hemsworth

Cate Blanchett

Freddie Highmore (it's actually harder for me to still picture him as August Rush or Jared Grace, and maybe that's why he does it (he was a child actor in those))

others

Did that help you remember?

I also learned that the Stella sisters are Canadian! They lived just an hour from me until they went to Nashville in 2009.

It was Chris Hemsworth - I saw him being interviewed on something or other. But rob, your linked article reminded me about Damian Lewis.
Jasdip - I remember the show but don't remember who played the Australian.

This is actually a pet peeve of mine. There was a scandal in England when an American actress was chosen to play Bridget Jones, and again when Gwyneth Paltrow played a Brit, though in both cases they were deemed to have done a good job. At the time, it was known that using American stars as leads would greatly broaden the interest (sales) in the U.S. Equally, TV shows made in the U.S. with Brits in prominent roles have done particularly well in the U.K. Therefore, I'm thinking all these Brits, Aussies and Kiwis playing Americans in lead roles are in a good part there for increasing sales in the UK and Commonwealth. I don't know if they also have an advantage in Canada (if they can get citizenship), where a certain amount of the actors in runaway U.S. productions must be Canadian.

Mind you, it's not that I have anything against all these foreign actors, individually (I don't count Canadians as "foreign"). It's just the number of them in lead roles, for what I believe to be venal reasons, when there are so many great American (and Canadian) actors, that bugs the heck out of me. Apparently, American actors' agents troll British drama schools looking for the next big thing. At least O'Laughlin and Baker, if I remember right, came here on their own looking for broader opportunities. Both had other shows before the ones where they became stars and they stuck around. Of course, they're the ones whose accents slip the most, too. :) They make up for it with charm. :)

So how do you feel about Jay Baruchel, plllog? :) Of course, there are many! Shatner and Jim Carrey off the top of my head. Looking it up, the Ryans (Gosling and Reynolds), Rachel McAdams...

It was a very good show. I knew that Gunner was British but not Scarlett.
Those sisters are just awesome talented girls. I hope fame doesn't ruin them like some other child stars.

Rob, just what I said. I have no issue with Canadians (or Mexicans) in U.S. productions, or vice versa. "The Biz" has always been fluid that way. Heck, the news had Peter Jennings, a Canadian! I'm glad to see more Canadian productions being shown on U.S. TV, though I'm less sure of which theatrical releases are Canadian productions until I see the Film Canada logo at the end. :) No issues with Canada protecting their actors in U.S. productions either. It's all so intertwined it's hard to draw a line. More importantly, while there are plenty of Canadian leads, and many successful Canadian actors move to Hollywood or New York to try to make it in a bigger pool, it's not like the producers are pushing out American actors to use them just because they're Canadian (outside of the ones produced in Canada, in which case it's fair). Sometimes a TV actor will start in a runaway U.S. TV show, gain a following and move to Hollywood to make movies. And there's similar traffic around the British Commonwealth due to the easier visa status.

There are far far more Brits, Aussies and Kiwis in lead or major roles in U.S. productions, however, than have been mentioned here. There was a show awhile back, Missing Persons, where it was a barrel of mixed pickles on the accents all trying to sound American, where most of them were Aussies. :) True Blood was populated by them all, though Anna Paquin is as much Canadian and Kiwi. :) The Wire probably chose Brits as leads for their low dollar demand for true excellence, but that doesn't explain the teeny bopper shows like Finding Carter. Damian Lewis and Kevin McKidd are fine actors, but I can't believe there aren't Americans who are just as good. The lead on Sons of Anarchy, which is about as American a culture as you can get was led by a Brit. Currently on TV, in addition to those mentioned previously, leads of Forever (Welsh, actually), The Americans (another Welshman), The Affair, and Walking Dead, are Brits. There are more.

When people talk about it, they usually talk about superiority of the English actors' training, but that doesn't account for the Aussies, nor that there are plenty of actors all around the U.S. who also get quality training, but they're not being sought out. Also, I don't begrudge the top talents like Idris Elba. I don't know that there is as skilled an American in his class and casting type. The lead of Sleepy Hollow is supposed to be a Brit, so that's fair. But I've heard that half the leads in Pilot Season went to Brits and Aussies.

As I said, pet peeve. Especially when the accent slips. :)