The 25-year-old underwent successful medical tests in Milan on Thursday morning before signing his contract at the Atalanta headquarters.
Sky Sport transfer expert Gianluca Di Marzio has reported that La Dea will pay €3.5m for a one-season loan with an option to buy for a further €16m plus up to €2.5m in bonuses.
Below is the video of Zaniolo arriving at the Atalanta offices to put pen to paper on an agreement with La Dea.