The entrepreneur-turned-Democratic candidate already has a solid list of celeb backing -- from Donald Glover to Elon Musk to Rivers Cuomo from Weezer -- but no big-time athletes ... yet.

Considering Yang's a big NBA fan, we asked -- hypothetically -- which baller he'd most want as his running mate ... and it took him like, a millisecond to give us his answer.

"I'd have to go with LeBron James," Yang tells us. "He's already shown he's got a heart of gold and loves the American people."

Yang showers the Lakers superstar with praise and throws some major shade at President Trump in the process ... saying, "He certainly could do better than the guy who's currently there."

Of course, Bron has shown support for Hillary Clinton in the past ... and even introduced her at a rally in Ohio.

LBJ has also made his feelings about POTUS crystal clear ... calling him a "bum" and a clown since #45 began his presidency.

Yang thinks LeBron would be a great addition to his team ... and gives him a personal message.