The defender spent last season at Parma, but has decided to hang up his boots at the age of 37.
"I had offers from the United States, but I just don't feel the same hunger anymore," he told Sky Sport Italia.
"I thank all the teammates I ever played with, the Coaches who trained me and the clubs I worked with.
"Looking back, the most exciting moment was winning the European Cup with Real Madrid, as I was the first Italian ever to lift the trophy with that shirt."
He also amassed 54 caps and four goals for the Azzurri.