Dwyane Wade -- Insane Prom Surprise ... Free Suits, Watches for Foster Kids

Dwyane Wade just hooked up 15 kids with a pretty awesome prom surprise -- free custom tailored suits and Hublot watches ... and they're about to get the goods at halftime of tonight's Miami Heat game.

Wade, along with Hublot, hooked up with the local Guardian ad Litem program -- and last week met with 15 kids from different parts of Florida who are all crushing it in the classroom.

To reward their success in school, Wade and Hublot hooked 'em up with D-Wade's personal stylist -- and a custom tailor -- so they could "suit up" in custom threads for their high school proms.

And get this ... Hublot also hooked the kids up with a free watch to boot ... and those things ain't cheap!!!