It seems to be a Hollywood chic to adopt a British accent for a UK role or 9even an ancient warrior), but the reverse is just as prevalent with Brits, Aussies, or other an actor of another nationality playing an American character. I realize that plenty of actors and actresses were born or even partially raised abroad, but this list is a reflection of actors whose primary dialect is not American. This list excludes Canadian actors/actresses.
Hails From: London, England
Noted Roles: Spiderman 2, Boogie Nights, a guest star on Law and Order SVU and Trial By Jury
Hails From: born in Ely, England, raised in Victoria, Australia
Noted Roles: Memento, Factory Girl, LA Confidential
Hails From: Bury St. Edmonds, England
Noted Roles: Who Framed Roger Rabbit, Hollywoodland
Hails From: Manchester, England
Noted Roles: Law and Order, RFK
Hails From: Perth, Australia
Noted Roles: Brokeback Mountain, The Dark Knight
Hails From: Oxford, England
Noted Roles: House MD
Hails From: Reading, England
Noted Roles: Eternal Sunshine of the Spotless Mind, Little Children, Titanic
Hails From: Haverfordwest, Wales
Noted Roles: Batman Begins, American Psycho
Hails From: London, England
Noted Roles: There Will Be Blood, Gangs of New York, The Crucible
Hails From: London, England
Noted Roles: Leon, The Fifth Element, and Romeo is Bleeding