The BBC is reporting that the Italian champions will pay £67.5m for the 19-year-old Ajax captain.
They've beaten off competition from the likes of Manchester United, Barcelona & Paris Saint-Germain to secure the teenager's coveted signature.
De Ligt came to the attention of Europe's elite last season after guiding his side to the Champions League semifinals and two major domestic trophies.
In his three seasons at Ajax, De Ligt won the Eredivisie and the Dutch Cup and was a Europa League finalist in 2017. He scored eight goals in 77 Eredivisie appearances for the club that he joined as a nine-year-old.
De Ligt scored eight goals in 77 league appearances for the Amsterdam club, who he joined at the age of nine, a decade ago. In March 2018 he became the club's youngest ever captain. Thirteen months before that, he made his debut for The Netherlands despite having only started two league games at that stage.
It's been quite a meteoric rise for the young centre back. We'll update you on the situation as it develops on futaa.com.