In the day's first semifinal, Ryan Evans and Ben Brust combined for 28 points as Wisconsin upended third-ranked Indiana 68-56.
Evans scored 16 points to go along with eight rebounds while Brust put in 12 for the Badgers (23-10), who recorded their 12th straight victory against the Hoosiers.
Jared Berggren and Sam Dekker each scored 11 points for Wisconsin.
The Hoosiers (27-6), who came up short in their bid for a first-ever Big Ten tourney title, got 14 points from Christian Watford, and 13 points and 11 rebounds from Cody Zeller.
The Badgers will take on Ohio State after Aaron Craft keyed a second-half surge for the Buckeyes in their 61-58 victory over seventh-ranked Michigan State in the day's second semifinal matchup.
Craft struck for 18 of his 20 points after halftime and distributed nine assists. Deshaun Thomas accounted for 16 points and seven rebounds as the streaking Buckeyes (25-7) reeled off their seventh straight win.
The Spartans (25-8), whose hopes of repeating as Big Ten champions evaporated, got 17 points and nine boards from Derrick Nix.
Keith Appling helped out with 16 points for MSU.