Steph Curry is the most famous person to EVER play basketball at Davidson College (by far!) ... so, why hasn't his jersey been retired?!

Simple -- Steph's gotta get his degree first. Seriously.

Remember, Steph is a LEGEND at Davidson, where he was a consensus 1st Team All-American and famously led the Wildcats to the Elite 8 in the 2008 NCAA Tournament.

So, when we spotted Steph's old college coach, Bob McKillop out in D.C., we had to get an explanation for why Steph's old #30 jersey ain't hangin' in the rafters.

TMZSports.com

"I think he's in the process of completing his degree," McKillop told us after heaping TONS of praise on his old player.

We followed up with the school and athletic director Chris Clunie told us that Steph is still actively working on his degree ... and as soon as he completes his education, boom -- the jersey gets retired.

Clunie says the school is extremely proud of all that Steph has accomplished on and off the court. They love the guy.