The superstar singer was one of the MANY famous faces in the crowd as the Lakers took on the Philadelphia 76ers at Staples Center in L.A. on Tuesday night ... and it was clear she's no fair-weather fan.

The video of Halsey is cool -- not only does she talk basketball, she signs autographs and takes pics with her fans after the game. Great stuff.

As for a potential Davis signing, it's possible -- but it would require the Lakers to give up almost all of their young stars ... Lonzo Ball, Kyle Kuzma, Brandon Ingram and others. They might also have to give up some draft picks.

It seems L.A. is where Davis wants to end up -- in fact, he was just fined $50,000 this week for "tampering" because NBA officials believe he broke league rules by demanding a trade.

Oh, and ... A.D. and LeBron have the same agent. Just sayin' ...

Should be interesting to see how this plays out.

Meanwhile, check out all the superstars at the game -- the Kardashians were there supporting Kendall's boyfriend, Ben Simmons.

Leo DiCaprio was also on hand ... same with Kevin Hart, Rami Malek, Diplo, Flea and Ashton Kutcher.