The Serie A champions have reached an agreement with the 19-year-old centre-back over a five-year contract that will see him earn €12 million (£11m/$13m) per season - €8m in basic salary with €4m in bonuses.
De Ligt's agent, Mino Raiola, confirmed to Dutch newspaper De Telegraaf on Sunday that a deal has been made with Juventus.
"Agreements have been made with Matthijs and it is up to Ajax how they deal with this," Raiola said.
Juventus have offered Ajax €65m (£58m/$73m) for De Ligt - €55m (£49m/$62m) up front with €10m (£9m/$11m) in bonuses, but the total falls around €10m short of the Dutch champions' asking price.
The Turin outfit do not see the the gap as insurmountable, however, and believe a deal will be made in the coming days, while new coach Maurizio Sarri has already spoken to the coveted star over the phone.
Despite his looming departure, De Ligt, who has also been linked with Paris Saint-Germain, Manchester United and Barcelona in recent months, returned to training with his Ajax team-mates on Monday as Erik ten Hag's side begin preparations for the new campaign.
As captain, De Ligt played a key role in his side's season, making 55 appearances in all competitions and scoring seven goals.
He will be Juve's fifth signing of the transfer window, as the Bianconeri have already landed Adrien Rabiot, Aaron Ramsey and Gianluigi Buffon, returning after a year with Paris Saint-Germain, in free deals, while Luca Pellegrini was bought from Roma and Merih Demiral arrived from Sassuolo.
Ajax, on the other hand, have already signed new centre-backs in 18-year-old Kik Pierie, who joined from Heerenveen, and Lisandro Martinez, while Quincy Promes and Razvan Marin also moved to the Dutch capital.
De Ligt will be the second major departure from Ajax this summer, as fellow rising star Frenkie de Jong has already left the Johan Cruyff Arena for Barca in a €75m (£67m/$84m) deal agreed in January.