The 18-year-old has committed himself to the club until the summer of 2018 after progressing through the ranks at the Serie A giants.
The teenager, who also holds a Canadian passport through his Canadian-born father, joined Milan in 2009 after playing amateur football in the Treviso region of Italy.
Cristante made his first-team debut for Milan as a substitute for Brazil star Robinho in the Champions League tie against Viktoria Plzen in the Czech Republic in December 2011. He also became the youngest player to feature in the Champions League for Milan at the age of 16 years and 278 days.
Cristante is no stranger to winning titles with the Rossoneri, despite his tender years. He scored eight times in the Under-15 squad win the Campionato Giovanissimi Nazionali in 2010 and followed that up with the Campionato Allievi Nazionali title a year later.
The midfielder possesses tremendous technique and strength, while his passing ability has also impressed Milan coach Massimiliano Allegri and his backroom staff.
Cristante works best in the midfield channels and has played in front of the defence before, but a similar role to Alberto Aquilani seems to be his favoured position. His ability from set pieces is also an asset.
The youngster is also making progress through the ranks with the national team, playing for the Italy Under-16, Under-17 and Under-18 teams.
Cristante will be a name to watch across Europe in the coming years.