The 1999–2000 Illinois State Redbirds men's basketball team represented Illinois State University during the 1999–2000 NCAA Division I men's basketball season.

The Redbirds, led by first year head coach Tom Richardson, played their home games at Redbird Arena and competed as a member of the Missouri Valley Conference.

They finished the season 10–20, 5–13 in conference play to finish in a tie for eighth place.

They were the number eight seed for the Missouri Valley Conference tournament.

They were defeated by Wichita State University in their opening round game.