The new winger was presented by the Italian team today after arriving in Milan on Wednesday morning and undergoing a medical.
Lyon and the Rossoneri submitted proposals to Chelsea for Pulisic, who made it apparent he wanted to join the Serie A powerhouses despite Lyon making the bigger offer at first.
The player has signed a four-year contract with Milan, with an additional 12-month option.
At the San Siro, 24-year-old Pulisic will don the No. 11 jersey, which was most recently worn by Zlatan Ibrahimovic. Several eminent individuals, like Rivaldo, Carlo Ancelotti, and Jean-Pierre Papin, have previously received the number for Milan.
After 145 appearances for the West London club, Pulisic leaves having scored 26 goals, including one in the Champions League semi-final match against Real Madrid before he assisted the squad in winning the championship in 2021.