The 24-year-old’s contract with Ajax was set to expire at the end of the season and AC Milan had agreed a pre-contract with AC Milan.
But the Rossoneri have agreed a €1.7million deal that will see the left wing-back join them now instead of at the end of the season.
“AC Milan announces the purchase from Ajax of Urby Emanuelson, who has signed a contract until June 30, 2014,” a club statement said.