Cop to Wiz Khalifa -- I Know Who You Are ... But You're Still BUSTED!

Wiz Khalifa learned two important lessons last night:

1) Always wear your seat belt
2) Being famous doesn't get you out of a ticket

TMZ spotted the rapper inside of his brand new $100k Porsche 911 Carrera S ... moments after he was pulled over by a cop for not buckling up ... a violation in the state of California.

Wiz -- who spent his day at a baby shower for his fiancee Amber Rose -- was clearly bummed out during the stop ... but turned to our camera and gave a message for his fans, "Make sure you guys wear your seat belts."

During the stop, we asked the cop if he knew he pulled over a world famous rapper -- to which he replied, "I know. I recognized him!"