Michael Jordan's personal check -- signed by His Airness -- made out to Donald Trump's Indiana casino during the '97-'98 NBA season ... just hit the auction block.
The one-of-a-kind check is dated "Feb. 16, 1998" ... and is made out to "TRUMP INDIANA, INC." -- Trump's now-closed riverboat casino in Gary, Indiana -- for 15,000 bucks.
MJ's very recognizable autograph is on the checks signature line ... above the font "JORDAN, MICHAEL J"
Michael's Bulls squad didn't have a game on February 16.