The 2009 Big Ten men's basketball tournament was played between March 12 and March 15, 2009 at Conseco Fieldhouse in Indianapolis, Indiana. It was the twelfth annual Big Ten men's basketball tournament. The championship was won by Purdue who defeated Ohio State in the championship game. As a result, Purdue received the Big Ten's automatic bid to the NCAA tournament. The win marked Purdue's first tournament championship in only their second appearance.