Did any NBA players not play high school basketball?

Answer 1

"Shoeless Joe" maybe?

Since all of the evidence indicates that "Shoeless Joe" Jackson of Chicago White Sox fame was illiterate, I'd think it is safe to assume that he didn't attend high school. It is also safe to assume that many other players in the early years of MLB didn't make it to the high school level.

Answer 2

For American players it's not very likely. I don't believe it has ever happened. In fact almost all have gone to College, although there are a few exceptions. But since in Europe sports are mainly organized in clubs outside school, there are some players who never played High School Basketball.

Steve Francis and many others did not play high school basketball.

Answer 3

Some, but not many.

Ex. Jason Bay, Adam Loewen, Erik Bedard, Darryl Hamilton, and maybe more that I dont know of.

Bryce Harper left high school after his sophomore year and Tanner Rahier from Southern California who was selected in the 2012 draft skipped high school Baseball entirely. Rahier chose to pass on HS baseball in order to spend the season training to play in his summer league. I think we will see a lot more of this in coming years as travel teams improve and offer superior training and competition.