The Via Turati side's draw with Roma this evening gives them an unassailable lead at the top of the league with two rounds still to play, assuring them of an 18th title.
AC Milan today clinched its 18th Serie A title by drawing 0-0 away to Roma. The goalless tie served to put city rivals Inter out of reach, with Milan now on 78 points with two games remaining
Despite the northern club's failing to hit the net, and finding itself under the pressure at the other end, Christian Abbiati and Alessandro Nesta helped to keep the capital side out and stretch the Rossoneri's lead at the top to nine points
Milan knew that a point would be enough to secure the Scudetto, as even if Inter wins its three remaining matches it can only match Milan's current total of 78; and having lost both the city derbies its head-to-head record renders it unable to lift the title without a points advantage.
Milan has led the table since late-November without being overhauled, though its lead was cut to two points at the end of March as Inter enjoyed a simultaneous resurgence.
However, the Rossoneri then embarked upon a six-match unbeaten run, starting with a stunning 3-0 derby win and culminating in this evening's result.
The title is the Diavolo's first since 2004, when they finished 11 points ahead of tonight's opponents Roma under coach Carlo Ancelotti, and comes in Allegri's first season on the bench.
The San Siro club has now won eight Scudetti during the reign of Italian prime minister Silvio Berlusconi as the club's president. Berlusconi recently celebrated 25 years at the helm of the club. He has also won five European titles in his time in Via Turati.