Do you know Pierre Boulle, the author of "Planet of the apes" and "Bridge on the river Kwaï"?

Question

It is a French writer but nobody knows it in France. Is it known in the rest of the world?

Answer 1

Yes, and he's known in the US mostly for the two books you've listed in your question. Another novel of his, "A Noble Profession" was also published here (I only know this because I own a paperback copy).
Since "Planet of the Apes", I don't recall any other work of his appearing here in the US---and that was some 40 years or so...which might explain why so few remember or know his work.

Answer 2

He's not well known (though he's not completely unknown), but surely he's better known in France than in the English-speaking world.