A versatile and creative player, Montolivo began his career with Atalanta in 2003 before joining Fiorentina in 2005. He went on to make more than 250 appearances for the club in seven years. In 2012, he signed for Milan on a free transfer and, following the departure of Massimo Ambrosini, served as the team's captain from 2013 until 2017, winning the 2016 Supercoppa Italiana. He left the club in the summer of 2019, before retiring later that year.