Stefano Pioli's side came into the final round of fixtures knowing a point would be enough for them to finish top ahead of rivals Inter Milan, with a double from Olivier Giroud and one goal from Franck Kessie sealing the Scudetto in style.
It is the first time that Milan have won the league title since Massimiliano Allegri guided the club to the trophy in the 2010-11 campaign.
Speaking after Milan's win over Atalanta last week, Pioli said he used NBA great Kobe Bryant as inspiration for his players.
The Los Angeles Lakers legend, who was tragically killed in a helicopter crash with his 13-year-old daughter Gianna, was a lifelong Milan supporter and grew up in Italy between the ages of six and 13.
"I showed the lads an interview with Kobe Bryant, who said at 2-0 up in the NBA playoffs, the job is not done. We're not done," Piolo said in his postmatch interview. "We need to maintain that calm and concentration that can in the end prove decisive.
"When we took charge at Milan, the team had completely different tactical ideals and concepts, so we had to change everything. Now the good thing is that the players enjoy making the most of our strengths and preparing tactically, being able to adjust also to limit our opponents."
Milan have now pulled level with city rivals Inter, who have 18 Serie A titles, to become the joint second-most successful club in league history behind Juventus, who have 36 league wins.