The 2009–10 Illinois State Redbirds men's basketball team represented Illinois State University during the 2009–10 NCAA Division I men's basketball season. The Redbirds, led by third year head coach Tim Jankovich, played their home games at Doug Collins Court at Redbird Arena and were a member of the Missouri Valley Conference. The Redbirds received an at-large bid to the 2010 National Invitation Tournament and were assigned the number six seed in the University of Illinois regional. They were defeated by the University of Dayton in the first round.