The arrival of Giampaolo is the first major decision made by the new backroom duo of Paolo Maldini and Zvonimir Boban, Milan's new technical director and chief football officer respectively.
Giampaolo led Sampdoria to ninth-place last season having previously coached Empoli, Brescia and Cagliari.
AC Milan, seven-time champions of Europe, have not played in the Champions League since 2013-14.
Having grown impatient with his former club's unwillingness to push on and spend money in the transfer market, I Rossoneri now provide the flawless platform for the 51-year-old to hone his skills as a football manager.
Qantas unveils Frequent Flyer overhaul
Photo Credit: A Qantas aircraft tailfin. "This is one of the most popular areas for people to redeem points", Joyce said. Qantas is also introducing a new Lifetime Platinum status for its most loyal members .