Benedicic has become the club's sixth summer signing just five days ahead of the 2014/15 Championship season. The 18-year-old is yet to make an appearance for the Milan first team but he has impressed in the club's U19's team.
The Slovenia U21 international has been training with his new teammates for several days and will add plenty of attacking threat to the Leeds attack.
Benedicic is an unknown quantity to many Leeds fans but it remains to be seen if he can deliver in English football.
Speaking about the deal, head coach Dave Hockaday said: “Zan is a versatile, strong and technical midfield player. He has massive potential and comes highly recommended by AC Milan.”
Owner Massimo Cellino now has four more days to make more signings before the start of the season. Although the squad looks thin and with a real lack of quality, United's new recruits have started to impress.