The former Manchester City striker has put pen to paper and completed his move to San Siro, ending a two-and-a-half year controversy-filled spell at the Etihad Stadium
The two clubs agreed a deal on Tuesday afternoon for £20 million that will be spread over five years, while the Italy international is taking a pay cut on his £110,000 per-week to join the Serie A side.
The 22-year-old Italy international brings an end to a controversial two-and-a-half-year stay in England with Roberto Mancini's side, during which he scored 20 goals in 54 league appearances, helping the club to win both the Premier League title and FA Cup, before moving back to his homeland.
"It's just Milan have acquired Mario Balotelli, he has signed a contract until 30.06/2017," AC Milan confirmed via their official twitter account.
With the move accelerating in recent days, Goal.com revealed on Thursday in a special report that the two clubs had been in constant dialogue with one another for the past two months over Balotelli's move back to Italy.