There is a Porn actor called James Deen (not his real name) who has attempted to move into non-porn acting. Hasn’t portrayed James Dean as far as I am aware.
TCMF-2L
There was a somewhat famous poet named Elizabeth Taylor.
There is a somewhat famous actor named Dave Thomas, like the Wendy’s founder Dave Thomas.
The director John Ford (who started as an actor) could have played a early British playwright named John Ford.
There was an actor named Ben Johnson, like an early British actor named Ben Johnson.
Henry Morgan could have played the pirate of that name.
Nicholas Rowe could play the early British poet of that name.
Jane Powell could have played the early British actress of that name.
The Australian actress Emma Hamilton could play the English model, dancer and actress.
The actor Walt Whitman could have played the author of that name.
The actor Fred Thompson could have played two other people of that name.
The actor and director John Waters could have played an earlier director of that name.
The actor Charles Hawtrey could have played the earlier actor of that name.
Imagine the possibilities for this guy:
Australian actor John Howard shares his name with a former Australian prime minister. In one episode of The Games, a comedy about the 2000 Sydney Olympics, the story line was that they were trying to get the PM to deliver an apology for previous government policy towards indigenous Australians, a very hot issue at the time. They got actor John Howard to do it instead, and disclaimed that it was ever going to be the PM. Nicely captured here.
Mentioned upthread, in fact:
Actor Christopher Lloyd could play producer Christopher Lloyd.
Given that the actor Christopher Lloyd is 22 years older than the producer of that name, when could he have played him?
Oops - so excited to add this one I didnt even check.
Just fire up the DeLorean, no problem.
In the movie “Fighting the Hypothetical.” As the list of actors who actually meet the OP’s criteria is apparently tiny (if not non-existent), most of the thread has been about hypothetical possibilities, no matter how farfetched.
I mean, the two Steve McQueens were mentioned upthread, and the one who is still alive is a black Englishman (and who is a director, not an actor), while the one who’s dead was a white American. As far as the actor playing the director, even more farfetched, as the actor died when the director was 11 years old.
…and the guy he steals them from is played by Mike Rowe
Close: Mark L. Chapman played John Lennon in a film about Mark D. Chapman murdering John Lennon.
Sigourney Weaver has never portrayed fictional character Sigourney Howard in The Great Gatsby (who she named herself after when she thought the name Susan was too ordinary).
Richard Dreyfuss played Colonel Georges Picquart in a movie about Alfred Dreyfus.
According to Wikipedia, he was on a number of shows like Fantasy Island and The Love Boat. Not exactly getting some major chops in the acting department there.
Are we allowing actors who took a famous name as a stage name? Seems like cheating.
Little-remembered actor John Marshall could have played well-remembered Supreme Court Chief Justice John Marshall.
Has that actually happened often? I know Desi Arnaz jr. played Desi Arnaz in The Mambo Kings, but your exception makes it sound fairly common.
Likewise for actor Anthony Edwards and basketball star Anthony Edwards.
Mind you, neither within the episode nor within the speech within the episode was John Howard actually playing John Howard. He was merely being John Howard making a speech. If that doesn’t make sense I am sorry.
Ruth Wilson played her own grandmother in a BBC drama called Mrs Wilson. That’s one.