The striker is on the verge of returning to Serie A after completing his medical on Wednesday afternoon but was greeted by hundreds of supporters, who clashed with police
The 22-year-old is on the verge of returning to Serie A in a £20 million deal and is currently in Italy ahead of the move, which is set to be officially completed on Thursday.
Balotelli had his medical at a hospital in Busto Arsizio on Wednesday afternoon and then went to have dinner with the club official after his three-hour examination.
Prior to meeting with Galliani, the Italy international was greeted by a large crowd of Milan supporters, who were chanting: "You threw the shirt of s**t [referring to Inter in the Champions League semi-final against Barcelona in 2010] on the ground, now you're with Milan. The dreams have come true, you score the best goals. We will win with Mario Balotelli."
The swarm of supporters also set off fireworks and police were required to use tear gas in order to break up the crowd.
A policeman was also taken to hospital after being hit on the head with a bottle which was thrown by one of the fans.