Do TV shows count? If so, I’m pretty sure that Commander Sinclair in Babylon 5, as well as Commander Sisko in the totally-not-a-ripoff Star Trek: Deep Space Nine, are both supposed to be in their early forties when they discover their Special Destinies as Valen and the Emissary respectively.
Bear in mind that at the time of his “choosing”, Dalinar was already a general and de-facto king, not to mention one of the most dangerous hand-to-hand fighters in the world, so it’s not exactly like he was plucked out of obscurity.
Missed OP’s cutoff (maybe on purpose), but Keanu Reeves was mid-thirties in the Matrix, and I think the official character (Thomas Anderson/Neo/ the One) is 37 at the beginning of the film.
In the Matrix Resurrections:
Carrie-Ann Moss(54) also becomes “the Chosen One” archetype by the end
In Larry Niven’s novel Protector, some 40-something guys become the saviors of humanity. Not sure it counts since there’s no mention of destiny and people are longer-lived in Niven’s future society.
How about the TV show Stan Against Evil with a 50ish John C. McGinley defending his home town from the supernatural?
Terry Brooks - Magic Kingdom for Sale - SOLD!
An interesting series. Rich 50 year old guy answers an ad in the paper to buy a magic kingdom. Turns out to be real, and he’s transported to another land to become its king. People don’t really care, as it happens a lot, but in this case, the guy CARES about it, and starts to make changes. A very nice series.
How about Master Li from Barry Hughart’s Bridge of Birds?
There’s no Chosen One in Bridge of Birds, but Ox is more the lead than Master Li is, in any case.
A slightly different kind of “chosen one” perhaps, but John Malkovich in Being John Malkovich
He wouldn’t be a “ripe vessel” until 44 IIRC.
Does Doctor Strange count?
Excellent user name/post combo.
Strange and I have a history.
Never mind. Totally mis-read the age part of the question.