Smart replaces Steve Wojciechowski, who was fired last week after seven seasons with the Golden Eagles.
"We undertook an exhaustive national search, during which we discussed our opening with a significant number of highly qualified coaches," Marquette athletic director Bill Scholl said in a statement. "Throughout the search, one individual continued to rise to the top and that was Shaka. I am beyond excited for our current and future student-athletes who will have the great fortune of being mentored by Shaka. He is a great teacher of the game, while also being a great molder of young men."
Smart, who turns 44 on April 8, becomes the first Black head coach in program history. He will be formally introduced at a Monday news conference.
"I am extremely excited to get to Milwaukee to begin building relationships and getting to work on the court!'' Smart said in a statement.
Among Texas' top targets to replace Smart is expected to be Texas Tech coach Chris Beard, who went to Texas and was a student assistant for the Longhorns under Tom Penders. His buyout to go to another Big 12 school drops to $4 million on Thursday, sources told ESPN.
Smart, a Wisconsin native, had been the head coach at Texas for six seasons. The Longhorns have gone to three NCAA tournaments under Smart but have yet to win an NCAA tournament game with him at the helm. They won the Big 12 tournament earlier this month but were then upset by 14-seed Abilene Christian in the first round of the NCAA tournament.
Smart had been on the hot seat in Austin for two years, but the pandemic likely saved him after the 2019-20 season. His buyout after this season for Texas would have been around $7 million.
Before taking over at Texas, Smart was the head coach at VCU, leading the Rams to five straight NCAA tournament appearances, including a Final Four run in 2011.