We got the actor Saturday in NYC, and he dished on what it was like working with Clint on his new movie "Richard Jewell" -- which documents the scandal surrounding the real-life security guard who found a bomb ... and then got accused of being the drop man.

PWH says he had a great time on set with with Clint, telling us the dude's a straight up sweetheart -- an ego-less one that. Plus, he's a freakin' icon ... that's a given.

We also ask Paul if it was intimidating to work with someone of that caliber, and surprisingly ... he says it wasn't, even if it should've been. That's interesting, considering what more seasoned actors have said about CE, which is pretty much the exact opposite.

Tom Hanks famously said in 2016 that Clint "treats his actors like horses" in the sense that he wrangles everyone up as needed, and was seemingly a bit of a hard ass on set.