The Rossoneri have announced their fourth signing of the winter window as the Morocco international joins until the end of the season with an option for a permanent switch
The Morocco international travelled to Italy on Thursday to undergo a medical and has now finalised his temporary move to San Siro on deadline day, with the club confirming the news via their official website.
Newly-appointed head coach Clarence Seedorf had demanded attacking reinforcements as he lacked options to play his preferred 4-2-3-1 formation and the Dutchman saw Taarabt as a useful addition to his front line.
The 24-year-old spent the first half of the season on loan at Fulham, but the Premier League side agreed to let go of Taarabt as he was not part of manager Rene Meulensteen's plans for the remainder of the campaign.
Taarabt previously wore the jerseys of Lens and Tottenham before joining QPR in 2010, with whom he has a contract until June 2016.
He becomes Milan's fourth signing of the January transfer window following the arrival of Adil Rami, Keisuke Honda and Michael Essien.