Vote in the poll and/or explain your answer!
The muscles from Brussels has a U.S. movie career that helped put his name in the public’s memory.
Personally, I prefer the Waffle but that wasn’t a choice.
Audrey Hepburn!
Yep. Followed by the painter Rubens.
Probably Rubens but I’m going with Eddy Merckx.
Google tells me the inventor of the Saxophone was a Belgian - Adolphe Sax.
King Leopold. (Specifically, Leopold II.) Made famous (or rather, infamous) for the brutality carried out in the Congo when it was his private fiefdom.
Albert Icomes to mind, who really led the Belgian Army in WWI, and fought with the troops.
Meet James Ensor, Belgium’s famous painter. Dig him up and shake his hand, appreciate the man.
Audrey Hepburn is a good choice, except I don’t think most people know she’s Belgian!
Rubens is also a good choice.
I don’t think most people are familiar with any kings of Belgium, but if they are, it’s probably Leo II.
The Belgian Waffle probably should have been a poll option…
I’d say Audrey Hepburn tops the list.
After that, well, a lot depends on whether you count people who were born in what’s NOW Belgium before the nation actually existed.
There were many great artists from Flanders, which is NOW part of Belgium. Van Eyck is just one who comes to mind.
Sigh. I knew someone else would get there first.
I thought first of Hercule Peroit (sp) and then Albert. I didn’t know that Audrey Hepburn is and Rubens was Belgian. 
Another vote for Leopold II who is in fact the only non-fictional Belgian I know (forgot Rubens’ nationality and had no idea about Audrey Hepburn).
I also forgot about Magritte. And I guess Herve although his creations are a lot more famous than he is.
The most famous Belgian is the Manneken Pis!
I came in to say this.
…wasn’t sure you & I would ever agree on anything, but yeah.
Even with Dreyfus, Hunter, Goodman, and ALL of Spielberg’s special effects, she STILL stole the movie ‘Always’.
(…good for Her! 
)
I thought Jacques Brel the singer-songwriter might rank somewhere up there… turns out he’s only the third best-selling Belgian musical artist of all time, the first being Salvatore Adamo.
Sprouts?
Georges Simenon, most “well-known” in the Biblical sense.