Johnny Manziel -- I CAN DUNK ... Here's the Video Proof

Johnny Football got hops.

The former Texas A&M quarterback -- who could be the #1 pick in the NFL Draft -- was messin' around on the basketball court with his college WR Mike Evans ... both showing off their dunking abilities.

Evans (6'5", 225) is clearly the superior dunker ... dude even threw down a nice 360 jam.

Oh, did we mention he did it all while wearing FLIP FLOPS?!

But Manziel (6'1", 210) proved he's got hang time too ... throwing down a two-handed dunk.

He was in basketball sneakers, tho.