The 26-year-old midfielder becomes a late signing for Italian champions as they look to boost their options in the centre of the park
An announcement on the Scudetto holders' website reads: "AC Milan communicates that it has acquired, outright, Antonio Nocerino from U.S Citta di Palermo, and he has signed a contract until 30 June 2016."
Nocerino spent three years with Palermo, making 122 appearances for the club, but becomes the latest player to be spirited away from la Favorita, joining the likes of Mattia Cassani, Javier Pastore and Salvatore Sirigu as summer departures.
Milan saw options in the centre of the park limited after receiving news of Mathieu Flamini's knee injury and have turned to the former Juventus midfielder to solve their problems.
Nocerino, an Italy international, first represented his country in a friendly tie against South Africa in 2007 and has gone on to win six caps for his nation.
Meanwhile, Ricardo Ferreira, a Portuguese defender signed by the Italian champions, will reportedly move to Palermo on a co-ownership deal as part of the arrangement.