From a contract in Manchester City at the end of June, the experienced midfielder agreed personal conditions with the Serie A title winners.
Transfer expert Gianluca di Marzio reports that De Bruyne will sign with the Azzurri in the coming days.
Contracts are arranged on Monday, with a final agreement that is now considered a formality.
De Bruyne will then undergo a medical before they put pen on paper with a two -year contract plus an option of 12 months.