celebrity strikers

[shinkyoku]

Noone has mentioned Dolph Lundgren yet. Kyokushin blackbelt and a former top level knockdown competitor in the late 70ies/early 80ies. He still practice kyokushin, and did a demo at the shinkyokushin world tournament last year.
Although he is an action star, he has never really done karate movies ("showdown in little Tokyo" excepted).

 

[shinkyoku]

I have heard both Mat Damon and Michael Rooker mentioned as former students of kyokushin karate (not at any high level, though). But that is not confirmed, and could very well be BS.